Annual Report 2004 - Institut für Halbleiter - JKU

ANNUAL REPORT 2004 

INSTITUTE FOR SEMICONDUCTOR AND 

SOLID STATE PHYSICS

Cover Figures 

Background shows an array of ordered SiGe islands, fabricated by seeded MBE 

growth on a Si substrate prepatterned using e-beam lithography. (Figure periodically 

repeated) 

Inset at bottom right shows the x-ray diffraction pattern around the (224) reflection of a 

similar structure: here, a multilayer of ordered SiGe islands grown on a prepatterned 

Si substrate forms a 3D-island-quasicrystal, giving rise to a large number of 

stallite peaks in reciprocal space.

INSTITUT FÜR HALBLEITER- UND 

FESTKÖRPERPHYSIK 

JOHANNES KEPLER UNIVERSITÄT LINZ 

ANNUAL REPORT 

2004 

PART A: Abteilung für Halbleiterphysik 

Semiconductor Physics Group 

PART B: Abteilung für Festkörperphysik 

Solid State Physics Group 

PART C: Christian Doppler Laboratory for 

Surface Science Methods 

PART D: Lehre, Seminare und Symposia 

Teaching, Seminars, and Symposia 

A-4040 Linz, Altenbergerstrasse 69 

Tel.: +43-(0)732-2468-9600 

Fax: +43-(0)732-2468-8650 

e-mail: halbleiterphysik@jku.at 

internet: http://www.hlphys.jku.at

Institut für Halbleiter- und Festkörperphysik 

Institute for Semiconductor and Solid State Physics 

Leiter / Head 

O.Univ.Prof. Dr. Günther BAUER 

e-mail guenther.bauer@jku.at 

Tel. +43-(0)732-2468-9600 

Fax +43-(0)732-2468-8650 

Abteilung für Halbleiterphysik Abteilung für Festkörperphysik 

Semiconductor Physics Group Solid State Physics Group 

Leiter / Head: Leiter / Head: 

O.Univ.Prof. Dr. Günther BAUER Univ.Prof. Dr. Wolfgang JANTSCH 

e-mail: guenther.bauer@jku.at e-mail wolfgang.jantsch@jku.at 

Tel. +43-(0)732-2468-9601 Tel. +43-(0)732-2468-9641 

Secretary: Secretary: 

e-mail: halbleiter@jku.at e-mail evelyn.rund@jku.at 

Tel. +43-(0)732-2468-9600 Tel. +43-(0)732-2468-9639 

Fax +43-(0)732-2468-8650 Fax +43-(0)732-2468-9696 

Redaktion / edited by: G. Brunthaler, L. Palmetshofer, S. Lechner, E. Rund, A. Stangl

Annual Report 2004 v 

Preface 

Following the scheme of previous annual reports, we describe in this report the academic, research 

and teaching activities of the Institut für Halbleiter- und Festkörperphysik in the year 

2004. This report is organized in four parts, one for each of the two subdivisions of the Institute, 

the Abteilung Halbleiterphysik (headed by G. Bauer) and the Abteilung Festkörperphysik 

(headed by W. Jantsch). The third part presents achievements of the Christian Doppler Laboratory 

headed by K. Hingerl, the fourth part gives an overview over the teaching activities of 

the institute. 

Graduations, scientific achievements 

In 2004, four people graduated from the institute as “Diplom-Ingenieur” and one PhD finished 

his studies successfully. They made important contributions to the scientific output of 

the institute. Again most of the papers of 2004 were published in Applied Physics Letters 

(12), there were 6 PRB’s and 1 PRL published under co-authorship of institute members. 

Among the highlights, there is the work on “ Two-flux composite fermion series of the fractional 

quantum Hall states in strained Si” by Lai et al. , which was done in collaboration with 

D.C. Tsui’s group at Princeton University. J. Stangl et al. published a review paper on “Structural 

characterization of semiconductor nanostructures” in Reviews of Modern Physics and 

on the cover page of the July 2004 issue of this journal appeared an AFM image of twodimensionally 

ordered Ge islands grown on patterned Si substrates by Zhenyang Zhong. In 

this year, the first vertically emitting IV-VI cw laser in the mid infrared was obtained in collaboration 

with the University of Bayreuth (Appl.Phys. Lett. 84, 3268 (2004), by J. Fürst et 

al) and an effective g-factor of up to 18000 was observed and reported for EuSe epilayers 

(Appl.Phys.Lett. 85, 67 (2004), by R. Kirchschlager et al.). Altogether the members of the 

institute published 22 papers in APS and AIP journals. 

Conference organization: 

In February 2004, Wolfgang Jantsch, Friedemar Kuchar (Monatuniversität Leoben) and myself 

organized the International Winterschool on New Developments in Solid State Physics: 

Low-Dimensional Systems in Mauterndorf with 253 participants from all over world. The 

programme followed the tradition of this school with invited papers presented by eminent 

speakers and poster contributions in the in the fields of spin-related phenomena, quantum Hall 

transport, magnetic semiconductors, quantum dot applications, quantum dot optics, quantum 

dot transport., photonic band gap structures and novel electronic devices. The chairpersons of 

the sessions were asked to provide thorough introductions into these fields and they did a 

marvellous job. As usual the conference organisation and the local organization put quite a 

burden on our secretaries and our students and their enthusiastic help was essential for the 

success of this meeting. 

Friedrich Schäffler took a lot of the burdens in organizing the 54 th annual meeting of the Austrian 

Physical Society chaired by P. Zeppenfeld, 28-30 September at the JKU and other institute 

members contributed as well. 

Awards and Prizes: 

Julian Stangl received the Förderungspreis of the Land Upper Austria for his work on “Determination 

of strains and chemical composition in self-organised semiconductor islands” 

and Rainer Lechner received an award of the Sparkasse Oberösterreich for his outstanding 

PhD thesis. Helmut Heinrich was decorated by the Federal Ministry of Economics and Labour

vi Annual Report 2004 

of the Republic of Austria with the Österreichisches Ehrenzeichen für Wissenschaft und 

Kunst 1. Klasse. 

NanoScience and Technology 

Under the leadership of Friedrich Schäffler, several institutes of the Technical/Natural- 

Science Faculty (TNF) of our University and the Upper Austrian Research (UAR) brought 

together a consortium of three companies and four research institutions which submitted a 

proposal “Nanstructured Surfaces and Interfaces” (NSI) in the first call for proposals of the 

Austrian Nano Initiative, incited by the Austrian Council for Research and Technology. This 

Upper Austrian project cluster was successful in receiving a funding of € 1.5 Mio in 2004, for 

six interlinked research projects for a duration of two years with work commencing in early 

2005. The NSI is coordinated by Friedrich Schäffler and cochaired by O Höglinger from the 

UAR and strengthens considerably the Nanoscience and Technology Center Linz (NSTL). 

Spezialforschungsbereich “IRON” 

A special research programme (Spezialforschungsbereich SFB 025) entitled “Infrared Optical 

Nanostructures” was established in collaboration with groups from the Technical University 

of Vienna, the Universities of Vienna and Jena, and the Technical University of Munich. The 

final decision on its funding was made by the Fonds zur Förderung der wissenschaftlichen 

Forschung, Vienna in October 2004 with the starting date of March 1 st , 2005. The principal 

investigators of five of the eleven granted projects are from this Institute in Linz. 

Apart from that, four new FWF projects (by W. Heiß, A. Bonanni, G. Springholz (2)) and two 

EU projects in which G. Bauer and K. Hingerl are partners, were granted. 

Structure and personnel 

By the end of the year, the Institute had 36 coworkers in the Halbleiterphysik, 31 in Festkörperphysik, 

and 10 in the CD lab, so altogether 79 persons were working in the semiconductor 

physics building of our University. 

Helmut Heinrich retired in 2004 and is professor emeritus since 30 September 2004. He 

founded the Solid State Physics group in Linz in 1972 which he led until 2003. Many of the 

present activities were initiated originally by him, e.g., ion implantation, epitaxy of IV-VI 

compounds, infrared detectors and emitters, and also the International Winterschool in Mauterndorf, 

together with G. Bauer and F. Kuchar. Among his scientific achievements, the socalled 

Heinrich- Langer rule attracted a lot of attention and it is still used to predict electronic 

leveles of transition metal impurities in semiconductors and band-offsets in heterostructures. 

He was Dean of the “Technisch-Naturwissenschaftliche Fakultät” in 1976-1979. In this period 

he committed himself successfully, among others, for the establishment of the Biophysics institute 

at JKU and he established the large instrument facility, now called TSE, which comprises 

instruments like electron microscopes, He- liquefier, etc.Helmut Heinrich was also the 

main driving force for a new chair in semiconductor physics in 1989 and 1990. He was president 

of the Austrian Physical Socienty (1978-80), board member of the Austrian Science 

Fund (1985-1994), of the Elektronik-holding and the VA Tech (ÖIAG) and chairman of the 

senate of the Christian Doppler Society (1995-2004). . 

Throughout 2004 our Rector had negotiations with the first candidate on the short list for the 

successor of Helmut Heinrich as a professor for Nanoscience and Ttechnology. Unfortunately, 

it was not possible to appoint the new professor before the end of 2004.

Annual Report 2003 vii 

Among the technical personnel, E. Heissl, K. Haselgrübler and S. Stadler left the Institute. We 

thank them for everything they did for us. New members – some of the well known already - 

are A. Praus, A. Stangl and E. Wirtl who joined us in 2004. 

Altogether 2004 was an eventful year. Here I would like to thank all institute members, students 

and co-workers for their work and enthusiasm, not only in their own projects, but also in 

all other activities of the institute. Herewith I would like to thank also all our partners and colleagues 

abroad for their help and collaboration and to our sponsors: 

◦ Johannes Kepler Universität, 

◦ Austrian Federal Ministry of Science, Education and Culture, 

◦ Austrian Federal Ministry of Infrastructure, 

◦ Austrian Science Fund (FWF), 

◦ Gesellschaft für Mikro- und Nanoelektronik (GMe), 

◦ Fonds zur Förderung der Gewerblichen Wirtschaft (FFF) 

◦ Oberösterreichische Landesregierung, 

◦ Österreichischer Akademischer Austauschdienst, 

◦ and the Funds of the European Union. 

Finally, I would like to thank Gerhard Brunthaler and Leopold Palmetshofer who accepted the 

tedious task of being editors for this report. 

Guenther Bauer Linz, September 2005

Table of contents 

Preface....................................................................................................................... v 

PART A: Semiconductor Physics Group ............................................ 1 

Personnel .................................................................................................................. 2 

Scientific staff..................................................................................................................2 

Technical and support staff............................................................................................3 

Visiting researchers ........................................................................................................4 

Research visits of institute members ............................................................................4 

Dozent assigned to the institute.....................................................................................4 

Research Overview................................................................................................... 5 

Research Initiatives .................................................................................................. 7 

SFB025-IRON (Infrared Optical Nanostructures) ..........................................................7 

Project Cluster Nanostructured Surfaces and Interfaces (NSI)....................................8 

Research Reports ................................................................................................... 11 

High mobility Si/SiGe heterostructures for Spintronics applications........................12 

Fabrication of long-wavelength vertical-cavity surface-emitting lasers....................14 

Resonator fabrication for tunable Si/Ge quantum cascade detectors.......................16 

Lateral quantum dots in high-mobility heterostructures............................................18 

Surface evolution of self-assembled PbSe quantum dots .........................................20 

Self-organization of ripples and islands with SiGe-MBE............................................22 

Transmission electron microscopy (TEM) of nanostructures....................................24 

X-Ray study of epitaxially grown GaP nanowires .......................................................26 

X-Ray diffraction from a SiGe island quasicrystal ......................................................28 

X-Ray investigation of thick epitaxial GaAs/InGaAs layers on Ge.............................30 

Metallic state in two-dimensional Si-MOS structures .................................................32 

Electronic structure of self assembled pyramidal PbSe quantum dots ....................34 

Magnetic properties of self organized EuSe quantum dots .......................................36 

Diploma and Doctoral Theses ............................................................................... 39 

Diploma theses finished in 2004 ..................................................................................39 

Current diploma theses ................................................................................................39 

Doctoral thesis finished in 2004...................................................................................39 

Current doctoral theses ................................................................................................39 

Publications ............................................................................................................ 41 

published 2004 ..............................................................................................................41 

submitted 2004 / in print ...............................................................................................44 

News Coverage..............................................................................................................46 

Talks and Presentations......................................................................................... 47 

Invited Talks ..................................................................................................................47 

Kolloquia and Seminar Talks........................................................................................47 

Conference Presentations (Talks and Posters)...........................................................48 

Funded Research Projects..................................................................................... 52 

Extramural Activities .............................................................................................. 55 

Gesellschaft für Mikroelektronik (GMe) .......................................................................55 

Fonds zur Förderung der wissenschaftlichen Forschung (FWF) ..............................55 

Industrial Collaborations........................................................................................ 56 

Organizational, Training, Awards.......................................................................... 56

Annual Report 2003 ix 

PART B: Solid State Physics Group ................................................. 57 

Personnel.................................................................................................................59 

Scientific staff................................................................................................................59 

Visiting researchers ...................................................................................................... 61 

Research visits of institute members .......................................................................... 62 

Research ..................................................................................................................63 

Research Reports....................................................................................................65 

Spin relaxation in zero dimensional SiGe islands ...................................................... 66 

Carrier-induced ferromagnetism in (Ga,Fe)N .............................................................. 68 

In situ characterization of MOCVD growth by x-ray diffraction ................................. 70 

Mid-infrared IV-VI vertical-emitting lasers ................................................................... 72 

Optoelectronic devices based on colloidal HgTe nanocrystals................................. 74 

Geometry dependent nucleation mechanism for SiGe islands.................................. 76 

Carrier mobility of Hot Wall epitaxially grown fullerene based transistors............... 78 

Diploma and Doctoral Theses................................................................................81 

Current diploma theses ................................................................................................ 81 

Current doctoral theses................................................................................................ 81 

Publications.............................................................................................................83 

published 2002 .............................................................................................................. 83 

submitted 2002 / in print ............................................................................................... 86 

Talks and Presentations .........................................................................................89 

Invited Talks ..................................................................................................................89 

Conference Presentations (Talks and Posters) .......................................................... 89 

Funded Research Projects .....................................................................................96 

Extramural Activities...............................................................................................97 

Industrial Collaborations ........................................................................................98 

PART C: CD Lab for Surface Science Methods................................ 99 

Personnel...............................................................................................................101 

Research Reports..................................................................................................102 

SOI material for 2D Photonic Crystal Applications................................................... 103 

Designing and Simulating disordered Photonic Crystals ........................................ 105 

Publications...........................................................................................................107 

Talks and Presentations .......................................................................................108 

Conference Presentations .......................................................................................... 108 

Talks at universities.................................................................................................... 108 

Visiting Researchers.............................................................................................108 

Research Projects .................................................................................................109 

PART D: Teaching, Seminars, and Symposia ................................ 111 

Winter Semester 2001/2002 ..................................................................................112 

Summer Semester 2002........................................................................................114 

Winter Semester 2003/2004 ..................................................................................117 

Semiconductor Physics Seminar Talks ..............................................................119

x Annual Report 2004

Part A 

Abteilung Halbleiterphysik 

– 

Semiconductor Physics Group

2 Personnel Part A: Semiconductor Physics Group 

Personnel 

The scientific-personnel structure of the semiconductor physics group consists of: 

◦ 2 permanent professor positions (granted by ministry of science), 

◦ 4 permanent scientific member positions (granted by ministry of science), 

◦ 2 full non-permanent scientific member positions (PhDs granted by ministry of science), 

◦ 16 non-permanent scientific member positions (granted by FWF, EC, ÖAD), 

Thus, for each permanent staff member an average of about 3 non-permanent research positions 

were acquired through granted research projects. 

Scientific staff 

Researchers funded by ministry of science 

name degree position 

Günther Bauer Dr. O. Univ.-Prof. 

Friedrich Schäffler Dr. Univ.-Prof. 

Gerhard Brunthaler Doz. Dr. Ao.-Prof. 

Gunther Springholz Doz. Dr. Ao.-Prof. 

Thomas Fromherz Dr. Univ.-Ass. 

Julian Stangl Dr. Univ.-Ass. 

Graduate (PhD) students 

name degree funding graduated 

Laurel Abtin M.Sc. FWF 

Thomas Berer Dipl.Ing. Univ. Linz 

Daniel Gruber Dipl.Ing. Univ. Linz 

Rainer T. Lechner Mag. FWF April 2004 

Herbert Lichtenberger Dipl.Ing. FWF 

Dmytro Lugovyy M.Sc. FWF 

Rajivsingh Mundboth M.Sc. FWF 

Jiri Novak M.Sc. EC (SiGeNET, SHINE) 

Dietmar Pachinger Dipl.Ing. FWF 

Georg Pillwein Dipl.Ing. FWF 

Patrick Rauter Dipl.Ing. EC (SHINE) 

Aaliya Rehman M.Sc. ÖAD 

Wolfgang Schwinger Dipl.Ing. FFF 

Mathias Simma Dipl.Ing. FWF 

Eugen Wintersberger Dipl.Ing. EC (SHINE), FWF

Part A: Semiconductor Physics Group: Personnel 3 

Post docs 

name degree funding 

Rainer Lechner Dr. FWF 

Mojmir Meduna Dr. EC (SHINE) 

Thomas Schwarzl Dr. FWF 

Diploma students 

name 

Martyna Grydlik 

Thomas Hörmann 

graduated 

Stefan Janecek July 2004 

Benjamin Lindner November 2004 

Bernhard Mandl (in co-operation with University of Lund, Sweden) 

Mathias Simma May 2004 

Eugen Wintersberger February 2004 

Technical and support staff 

name position 

Friedrich Binder mechanic 

Stephan Bräuer clean room technician 

Alma Halilovic laboratory technician 

Ursula Kainz a laboratory technician 

Antonia Praus b laboratory technician 

Susanne Lechner, Mag. administration 

Sabine Stadler c administration 

Alexandra Stangl d administration 

Ernst Vorhauer, Ing. (HTL-Elektronik) electronics engineer 

a till 7. Nov. 2004, b since 8. Nov. 2004, c Jan. – Nov. 2004, d since Dec. 2004

4 Personnel Part A: Semiconductor Physics Group 

Visiting researchers 

name home institution duration 

Vaclav Holy, Prof. Charles Univ. Prag 2 months 

Sigurd Wagner, Prof. Princeton Univ. 1 month 

Research visits of institute members 

name visit to 

G. Bauer DESY Hamburg, ESRF Grenoble, Masaryk Univ. Brno 

R. Lechner DESY Hamburg, ESRF Grenoble 

J. Stangl DESY Hamburg, ESRF Grenoble 

E. Wintersberger DESY Hamburg, ESRF Grenoble, Masaryk Univ. Brno 

A. Rehman DESY Hamburg, ESRF Grenoble 

Dozent assigned to the institute 

name permanent address 

Ernest Fantner, Doz. Dr. IMS Wien

Part A: Semiconductor Physics Group: Research Overview 5 

Research Overview 

Nanostructures 

The central research focus of the institute is on semiconductor hetero- and nanostructures, 

thus forming a strong building block of the “Nanoscience and Technology” research activities 

of the Johannes Kepler University Linz. The research work at our institute encompasses all 

aspects of semiconductor nanostructures, ranging from nanofabrication, to fundamental investigations 

and modeling of physical properties, up to the realization of novel nanostructure devices. 

Nanostructures are fabricated using advanced lithography and processing techniques 

such as electron beam lithography as well as by self-assembly based on molecular beam epitaxy. 

For these purposes, a class 100 clean room facility with all the necessary processing 

equipment is run at the institute. The objective of nanofabrication is to produce defect free 

structures in the sub 50 nm range with good control of shapes and compositions with sharp 

heterointerfaces and excellent optical and electronic properties. A particular emphasis is on 

the development of site-control techniques for positioning of self-assembled nanostructures. 

Physical Properties 

The fundamental structural, electronic, optical and magnetic properties of nanostructures are 

studied using a wide range of techniques. These range from advanced x-ray scattering techniques 

using synchrotron radiation, high-resolution electron microscopy, scanning force and 

scanning tunneling microscopy, optical spectroscopy as well as low temperature magnetotransport 

measurements. The focus of research is to correlate the electronic properties of 

nanostructures with the fabrication processes and structural properties, taking advantage of 

the complementarity of information gained by the available wide range of techniques and 

modeling tools. A strong emphasis is on infrared spectroscopy of the interband and instersubband 

electronic transitions in SiGe and narrow band gap semiconductors heterostructures, as 

well as on ballistic and quantum transport studies of SiGe and III-V hetero- and nanostructures 

in the milli Kelvin temperature regime. In addition, the magnetic properties of magnetic 

semiconductor hetero- and nanostructures are investigated and novel tools for nanostructure 

investigations based on synchrotron light sources are developed. 

Devices 

Several research activities are devoted to the fabrication of semiconductor hetero- and nanostructure 

devices, ranging from mid-infrared intersubband and interband detectors, quantum 

cascade structures, mid-infrared vertical cavity surface emitting lasers, resonant cavity detectors, 

to transport devices such as quantum dot and single electron transistors. In addition, 

novel spintronic devices that take advantage of the spin degree of freedom in order to produce 

new functionalities are developed. 

Materials 

From the materials side, a strong focus is on Si/SiGe/SiGeC based hetero- and nanostructures 

for which a large molecular beam epitaxy system is operated in the clean room of the institute. 

In addition, there is extensive work on narrow gap IV-VI compound semiconductors, which 

includes PbSe as well as PbTe based materials as well as the magnetic europium chalcogenide 

semiconductors. For these materials another two molecular beam epitaxy systems are available 

at the institute. The fabricated structures are supplied also to external research groups 

outside of the institute in the framework of long term international collaborations. On the 

other hand, also materials and structures including SiGe as well as GaAs/GaAlAs based structures 

are supplied from outside groups for further processing and analysis with techniques developed 

at our institute.

6 Research Overview Part A: Semiconductor Physics Group 

The research activities are embedded in several large research initiatives and project clusters 

such as the IRON special research program, the NIS Nanostructured Surface and Interface 

project cluster, as well as the SANDiE European network of excellence and several other EU 

funded research projects, more details are given in the other parts of the annual report. 

Experimental facilities 

Growth of low dimensional semiconductor heterostructures: 

◦ Riber SIVA SiGeC molecular beam epitaxy system 

◦ Riber 1000 and Riber 32 molecular beam epitaxy system for IV-VI semiconductors 

◦ Varian Gen II molecular beam epitaxy system for IV-VI semiconductors 

Processing and fabrication of nanostructures: 

◦ 200 m 2 clean room with areas of class 100 – 10000 

◦ optical lithography (mask aligner) for front and bottom side 

◦ holographic lithography 

◦ electron beam lithography 

◦ reactive ion etching 

◦ SiO2, Si3N4 plasma deposition 

◦ electron beam evaporation system for metallization 

◦ wafer bonder 

◦ diffusion ovens 

Surface analysis, structural, optical, electrical, and magnetic investigations: 

◦ UHV-scanning tunneling microscopes 

◦ Atomic force microscopes 

◦ Scanning electron microscope 

◦ Nomarski microscopes 

◦ Three high-resolution X-ray diffractometers, one with multilayer x-ray mirror 

◦ Rotating anode X-ray system with four-circle diffractometer 

◦ Two Fourier-transform infrared spectrometers including cryostats and magnet systems 

◦ Photoluminescence setup (Ar ion laser, Nd:Yag laser, grating spectrometer) 

◦ CO2 and CO lasers for spectroscopy 

◦ Several high-field and low-temperature superconducting magnet systems with He3 cryostat 

(8 and 16 T, down to 0.3 K) 

◦ SQUID-susceptometer for magnetization studies 

◦ Parmeter analyzer and LCR bridge 

◦ Wafer Probe

Part A: Semiconductor Physics Group: Research Initiatives 7 

Research Initiatives 

Special Research Programme SFB025-IRON: „Infrared Optical 

Nanostructures“ 

Günther Bauer 

In 2004 one of the main activities was the preparation of a proposal for a special research programme 

together with groups from the Technical University of Vienna, the theory groups 

from the University of Vienna, the Technical University of Munich and the University of Jena. 

These efforts were successful and after getting approval from an international review panel 

with scientists from the United Kingdom, Sweden, Switzerland and the USA in September 

2004, in October 2004 the FWF finally provided funds for the first four years, starting with 

March 1 st 2005. If successful, the SFB 025 has the chance of getting prolonged for additional 

six years, thus its entire duration can last for 10 years. For the scientists involved ( F. Schäffler, 

Wolfgang Heiß, Gunther Springholz, Thomas Fromherz, Julian Stangl, and Günther 

Bauer) from the Institut für Halbleiter-and Festkörperphysik in Linz, in total 10 PhD and postdoc 

positions were granted. This SFB, the third one granted by the FWF in the field of physics 

in Austria, will undoubtedly have a strong impact on the future research activities of the 

institute in Linz. 

The objective of this "Spezialforschungsbereich IRON" is to employ semiconductor nanostructures 

in order to overcome the shortage of efficiently functioning optoelectronic semiconductor 

devices in the 2 to 20 µm wavelength range. In order to achieve this goal we plan to 

make significant advances in the understanding and development of novel nanostructuers for 

future midinfrared devices. 

Its mission is defined by the following scientific goals: 

1) to obtain new physical insights in carrier and spin dynamics, infrared response, energy 

level schemes and many body effects in quantum confined nanostructures 

2) to advance state of the art nanofabrication through self-assembled growth of quantum dots , 

their ordering on prepatterned substrates as well as by epitaxial integration of chemically 

synthesized nanocrystals and by modelling growth dynamics 

3) to develop novel infrared quantum dots devices by exploiting and engineering the singular 

density of states, by tuning of the electronic coupling between quantum dots and by photon 

confinement using photonic band gap structures. 

Furthermore it will establish long term interdisciplinary partnerships between leading research 

institutions in Austria and Germany, and broadly train and educate young researchers in the 

fields of nanotechnology, infrared photonics, spin photonics, quantum physics and optoelectronics. 

More information: http://www.hlphys.uni-linz.ac.at/hl/IRON_SFB/IRON_SFB.html 

Funding: FWF, GME 

Corresponding Author: Guenther.Bauer@jku.at

8 Research Initiatives Part A: Semiconductor Physics Group 

Project Cluster Nanostructured Surfaces and Interfaces (NSI) 

F.Schäffler 

Three years ago the Austrian Council for Research and Technology Development proposed an 

Austrian Nano Initiative to strengthen the national activities in the 

field of NanoScience and Technology. In 2004 FFG and FWF, the 

two funding agencies administering the program, issued the First 

Call for Program Line I: Project Clusters in this emerging interdisciplinary 

field. The Johannes Kepler University (JKU) and Upper 

Austrian Research (UAR), the research institution of the province 

of Upper Austria, brought together a consortium of three companies 

and four research institutions, which participated in the First 

Call with their proposal Nanostructured Surfaces and Interfaces (NSI). Following the suggestions 

of an international refereeing board, five out of a total of eight consortia proposals submitted 

to the First Call were awarded funding for a two-year period each. The project cluster 

NSI, which consists of six interlinked research projects, receives funding of € 1.5 Mio. NSI is 

coordinated by F. Schäffler from the Institut for Semiconductor Physics; and co-chaired by O. 

Höglinger from UAR. Project work is scheduled to commence in early 2005. 

The purpose of NSI is, to link the expertise and infrastructure in the field of NanoScience 

and Technology, which was systematically developed since the early 1990s in Linz and Upper 

Austria, and to make them available to both the Austrian industry and to education inside and 

outside the university. NSI is expected to convert the as yet loosely linked NanoScience and 

Technology activities in Linz into a nationally and internationally competitive center of excellence. 

It is intended to develop NSI into a local node in the emerging Austrian NanoScience 

and Technology Network, located in Upper Austria, the leading industrial center of Austria. In 

terms of education, the research projects of NSI provide qualified research positions for the 

students of the first Austrian NanoScience and Technology course, which was launched in 

2002 at the Johannes Kepler University in Linz. 

NSI covers three of the four main competence areas of the NanoScience and Technology 

activities in Linz and Upper Austria, and makes them available to the concept of the Austrian 

Nano Initiative. These three competence fields are Biocompatible Nanostructures, Polymers 

and Nanocomposites, and Metal Surfaces and Interfaces. Semiconductor Nanostructures, the 

fourth core competence in Linz, is already more advanced regarding its national and international 

integration and will mainly be pursued in the recently installed, international Spezialforschungsbereich 

IR-ON. Links between NSI and IR-ON exist via participation of the Institute 

for Semiconductor and Solid State Physics in several of the NSI projects. This way the 

expertise and infrastructure available in and around the cleanroom of the institute is made 

available in an interdisciplinary approach to the other core competence areas. 

In the following, the six projects of NSI are briefly outlined, ordered with respect to the 

three aforementioned competence areas. The structure of IR-ON is treated in a separate article 

in this annual report. 

1. Biocompatible Nanostructures 

1.1 Nanostructured und Biofunctionalized Surfaces (NABIOS). In this project methods and 

techniques from semiconductor technology and surface science are combined with molecular 

chemistry and single molecule spectroscopy. In a first step, gold surfaces are nanostructured 

by e-beam lithography at the Institute for Semiconductor Physics. Simultaneously, the Insti-

Part A: Semiconductor Physics Group: Research Initiatives 9 

tute for Biophysics develops linker molecules that allow binding of a single bio-molecule on 

each of the nanopatterned Au islands. Finally, UAR provides single molecule detection using 

the fluorescence microscope ("nanoreader") they developed recently in the framework of the 

national GEN-AU project. NABIOS combines in an interdisciplinary way the technologies an 

expertise of groups in three differen fields of NanoScience and Technology. 

1.2 Nano-Biocompatible Polymerfoils (NBPF). In this project the surfaces of polymer foils 

are nanostructured by laserradiation in a way that allows the ordered arrangement of cell cultures 

for medical diagnosis and therapy. This approach provides a local modification of the 

polymer surface that avoids the disadvatages of conventional techniques, such as reduced mechanical 

stability or enhanced bio-degradation. The consortium comprises the institutes for 

Applied Physics and Biophysics (both JKU) for laser patterning and bio-compatibility, and 

the Institute for Pharmacology and Toxicology (Univ. Vienna) for the automatic positioning 

of cell cultures. 

2. Polymers und Nanocomposites 

2.1 Nanometric Organic Actuators (NANORAC). This entirely new approach employs organic 

semiconductors to realize nano-electromechanical (NEM) functionality. As yet, dielectrics 

were utilized for such purposes, which are not easily integrated into electronic circuits. The 

new approach aims toward organic actuators that can be controlled by integrated organic electronic 

components. NANORAC combines the expertise of the Linz Institut for Organic Solarcells 

(LIOS) und der Group for the Physics of Soft Matter, both from JKU. 

2.2 Sol-Gel-enhanced Catalysts for the Fabrication of Carbon-Nanotubes (SolTube). Carbon- 

Nanotubes (CNT) are an intense research area for a large number of potential applications.. 

SolTube introduces a Sol-Gel-Process for the deposition of a homogeneous dispersion of Nanopartikels 

on a surface. These then work as catalysts for the growth of a densely packed 

CNTs. In the long run, membranes consisting of dense arrays of CNTs are envisaged for nanofiltration 

purposes. SolTube is led by the company Profactor from Steyer near Linz, which 

provide the sol-gel process. Electrovac, a leading European manufacturer of CNTs provides 

the facilities for the growth of CNTs. This project is supported by the analytical tools and expertise 

in CVD growth of CNTs available in university institutes in Linz and at TU Vienna. 

3. Nanostructured Metal Surfaces and Interfaces 

3.1 Optical Properties of Metal Clusters on Crystalline Surfaces (MetClust). In this project 

the basic properties of nanometer-sized metal clusters on crystalline PET und quartz- 

Oberflächen are investigated with optical und magneto-optical methods. In particular, Reflectance 

Difference Spectroscopy (RDS) will be employed, a field in which pioneering contributions 

were made in Linz. The project is coordinated by the Institute for Surface Science, with 

contributions from the Institute for Solid State Physics, and the company Hueck Folien. 

3.2 In-Line-Characterization of Nanometer-Thick Metallayers on Polymerfoils (PolyMet). 

This project is closely related to MetClust, and aims toward an exploitations of the optical 

techniques developed in MetClust for industrial surveillance of foil production lines. For this 

purpose a prototype set-up will be developed for in-line control of nm-thick metal films on 

polymer foils. This project is a collaboration between Hueck Folien and the Institute for Surface 

Physics. 

More Information: www.nanoscience.at 

Funding: Austrian Nano Initiative (FFG, FWF) 

Corresponding Author: Friedrich.Schaffler@jku.at

10 Research Initiatives Part A: Semiconductor Physics Group

Part A: Semiconductor Physics Group: Research Reports 11 

Technology and devices 

Research Reports 

◦ High mobility Si/SiGe heterostructures for Spintronics applications 12 

◦ Fabrication of long-wavelength vertical-cavity surface-emitting lasers 14 

◦ Resonator fabrication for Si/Ge quantum cascade detectors 16 

◦ Lateral quantum dots in high-mobility heterostructures 18 

Growth phenomena 

◦ Surface evolution of self-assembled PbSe quantum dots during overgrowth 20 

◦ Self-organization of ripples and islands with SiGe-MBE 22 

Structural, electronic, and optical characterization 

◦ Transmission electron microscopy (TEM) of nanostructures 24 

◦ X-Ray study of epitaxially grown GaP nanowires 26 

◦ X-Ray diffraction from a SiGe island quasicrystal 28 

◦ X-Ray investigation of epitaxial GaAs/InGaAs layers on Ge 30 

◦ Metallic state in two-dimensional Si-MOS structures 32 

◦ Electronic structure of self assembled pyramidal PbSe quantum dots 34 

◦ Magnetic properties of self organized EuSe quantum dots 36

12 Research Reports Part A: Semiconductor Physics Group 

High mobility Si/SiGe heterostructures for Spintronics applications 

D. Gruber, H. Malissa, D. Pachinger, F. Schäffler, W. Jantsch, 

A. M. Tyryshkin 1 and S. A. Lyon 1 

The Silicon Germanium (SiGe) material system is a promising candidate for solid-state spintronics 

applications due to its very long spin relaxation times and its compatibility to standard 

Si process technology. There are proposals for spin transitors in the SiGe material system 

which could be used for Quantum Computing. For this application very long spin coherence 

times and the ability to control and to read spin orientation is necessary. We work towards the 

demonstration of the ability to control the g-factor of electron spins in SiGe Quantum well 

structures by applying electrical fields, which can be used for selective spin manipulation. 

Our samples are grown in a Molecular Beam Epitaxy (MBE) system with electron beam 

evaporators for Si and Ge. The channels are n-type modulation-doped with Sb. High mobilities 

of up to µe = 250,000 cm 2 /Vs have been reached in pure Si channels without back gate. 

The spin lifetimes are extremely long as well: Spin-echo measurements give T1 = 2.3 µs and 

T2= 3 µs for a magnetic field perpendicular to the 2DEG plane [1]. The high quality of our 

samples was also shown in recent magneto-transport experiments, where the ν=1/3, 4/7 and 

4/9 composite fermion states in the fractional quantum Hall effect were seen for the first time 

in the SiGe material system [2].The samples are either pure Si wells or double quantum well 

(QW) structures with a pure Si well and one with 5% Ge, which are separated by a barrier 

with 15% Ge content. The second structure is designed in a way that by applying electrical 

fields relative to the quantum wells one can completely shift the electronic wave function 

from one well to the other as depicted in a self-consistent band structure simulation in Fig. 1. 

Hand in hand with the change in the surrounding material goes a change in g-factor of the 

electrons [3] and hence a change in resonance frequency in an Electron Spin Resonance 

(ESR) experiment. Spin manipulation via pulsed ESR techniques is then possible on the spins 

which have been shifted into resonance. 

Fig. 1: Self-consistent band structure calculation of the double quantum well structure (as 

shown above and right) with different applied backgate fields: A front gate was used to keep 

the carrier concentration at a constant density of ns=3x10 11 cm -2 . The calculated change in gfactor 

can be estimated as ∆g = 2.5x10 -4 , which is enough to separate the resonances and 

allow spin manipulation. 

The required electrical fields are created by applying voltages to a Schottky-type topgate 

and either a grown-in n-type backgate or an evaporated Al backgate on the backside of the 

sample. Fig. 2. shows how the carrier density and the mobility can be changed in a pure Si 

channel with Schottky topgate and evaporated Al backgate. Our next goal is the combination 

of front- and backgate and the double QW structure.


Fig. 2: Carrier density and mobility of a sample with pure Si channel with a Pd Schottky gate 

on top and an evaporated Al backgate on the back side plotted as a function of the topgate 

voltage for different backgate voltages. Both mobility and carrier density can be influenced 

by shifting the wave function away from the interface (higher backgate voltages). 

In summary, we report about a SiGe double QW structure designed for tuning the electronic 

g-factor of electrons. Simulations show that it is possible to completely shift the electronic 

wave function between two wells with different Ge content and hence the g-factor 

which is a requirement for quantum computing in SiGe. The process for top- and backgate 

electrodes is established, and demonstrated on a single Si well sample. The next step will be 

the combination of double QW structure and front- and backgate. 

References 

1. A. M. Tyryshkin, S. A. Lyon, W. Jantsch, and F. Schäffler, PRL 94, 12802 (2005) 

2. K. Lai, W. Pan, D.C.Tsui, S. Lyon, et al., PRL 93, 156805 (2004) 

3. H. Malissa, W. Jantsch, M. Mühlberger, F. Schäffler, Z. Wilamowski, M. Draxler, and P. Bauer, APL 85, 

1739 (2004) 

Collaborations 

A. M. Tyryshkin 1 and S. A. Lyon 1 , Department of Electrical Engineering, Princeton University, Princeton, NJ 

08544 USA 

Funding 

FWF, GME 

Corresponding Author: daniel.gruber@jku.at


Fabrication of long-wavelength vertical-cavity surface-emitting lasers 

with cw emission at 6-8 microns 

G. Springholz, T. Schwarzl, M. Böberl, W. Heiss, J. Fürst 1 , and H. Pascher 1 

Narrow bandwidth coherent mid-infrared emitters of great importance for ultrahigh-sensitive 

gas analysis and atmospheric pollution monitoring because the strong absorption lines of all 

molecular gases are found in this spectral region. The IV-VI semiconductors are particularly 

very well suited for these devices due to their nearly symmetric conduction and valence bands 

and the very small non-raditative Auger recombination rates. Over the last few years, we have 

developed a novel class of MIR lasers based on ultra-high finesse epitaxial vertical cavity 

structures. The resulting IV-VI vertical cavity surface emitting lasers (VCSELs) offer several 

advantages such as very small beam divergence, single mode operation and the possibility of 

monolithic integration. In addition, they can be grown on readily available BaF2 substrates, 

which have a much higher thermal conductivity than high-cost IV-VI substrates. 

In the present work, we report the fabrication and operation of the first infrared VCSELs 

operating in cw mode at very long wavelengths up to 8 µm. The structures were grown by 

molecular beam epitaxy on (111) oriented BaF2 [1]. As PbSe emits at wavelengths longer 

than 6.5 µm only at cryogenic temperature, the lasers were designed for operation temperatures 

below 100 K. The microcavity structure is formed by two high-reflectivity epitaxial 

Bragg mirrors consisting of five λ/4 EuSe/Pb0.94Eu0.06Se layer pairs. Due to the high refractive 

index contrast a reflectivity of 99.5% is achieved already by a few layer pairs. The 2 λ cavity 

region of the VCSEL designed for 7.9 µm emission wavelength consists of a 2.2 µm 

Pb0.94Eu0.06Se buffer and a 1.1 µm PbSe active region. 

Figure 1 (a) shows the reflectivity spectrum of the VCSEL. At 300 K, the spectrum exhibits 

three narrow cavity resonances of m = 3 rd , 4 th and 5 th order. The line width of the central 

4 th order mode is only 0.10 meV, demonstrating a high finesse of 400. Owing to the decrease 

of the PbSe band gap, at low temperatures the higher energy cavity resonances are damped by 

interband absorption. Thus, at 60 K (see insert), the 4 th order cavity resonance is broadened to 

0.13 meV and disappears at even lower temperatures. The VCSELs were optically pumped 

using a 5.28 µm cw-CO laser and the total emitted power was measured using a calibrated 

detector using an InSb long pass filter. Figure 1 (b) shows the emitted laser line for cw as well 

as pulsed excitation. At 2 K, laser emission is found at the 4 th order resonance at 156.51 meV 

or λ = 7.92 µm, which represents the longest emission wavelength of all VCSELs reported to 

date. For cw operation, an extremely narrow line width of only 12µeV or 0.6 nm is observed. 

Reflectivity (%) 

100 

90 

80 

70 

60 

50 

40 

30 

20 

10 

0 

(a) 7.9 µm VCSEL 

0.1 meV 

FWHM 

300 K 

m=3 

m=4 

m=5 

Transmission (a.u.) 

60 K 

m = 4 

FWHM 

0.13 meV 

158.0 158.5 

120 140 160 180 200 

Energy (meV) 

220 240 260 

Normalized emission 

(b) 

excitation power 

400 mW 

cw 

FWHM 12 µeV 

(spectrometer 

resolution) 

7.9 µm VCSEL 

2 K 

pulsed 

FWHM 45 µeV 

156.40 156.44 156.48 156.52 156.56 156.60 

Energy (meV) 

Figure 1: (a) Reflectivity of a 7.9 µm cw-PbSe/EuSe VCSEL measured at 300 K. The insert 

shows the transmission around the central cavity mode at 60 K on an enlarged scale. (b) 

Emission spectra at 2 K in cw (dots) and pulsed mode (triangles) at 400 mW pump power.


Emission Power (mW) 

10 0 

10 -2 

1x10 -4 

2 K 

7.9 µm VCSEL 

cw emission 

stimulated emission 

spontaneous emission 

Emitted Pulsed 

Peak Power (W) 

10 

1 10 100 1000 

-8 

10 -6 

5 

0 

0 100 200 300 400 500 

Pulsed Pump Power (W) 

CW Excitation Power (mW) 

25 

20 

15 

10 

pulsed emission 

(a) 

Emission Power (mW) 

0.4 

0.3 

0.2 

0.1 

7.9 µm VCSEL 

(b) 

0.3 

(mW) 

0.2 

Power 

cw excitation power 

0.1 

130 mW Emission 

0.0 

0 10 20 30 40 50 

Temperature (K) 

Figure 2: (a) Cw output power of the 7.9 µm VCSEL plotted as a function of pump power at 2 

K: (o) spontaneous emission, (●) laser emission. The 25 mW laser threshold is determined 

from the inflection point. Inset: pulsed laser output versus excitation power. (b) Cw output 

power of the same VCSEL at 130 mW pump power plotted versus operation temperature. 

This is 10 times smaller than width of the unpumped cavity resonance. It is also much narrower 

than that of the pulsed mode emission of 45 µeV (2.3 nm), whereas for cw-excitation it is 

exactly equal to the resolution of the spectrometer setup. Thus, the true cw line width is actually 

much smaller than 0.6 nm [1]. 

Figure 2 (a) shows the logarithmic plot of the cw power emitted as a function of excitation 

power. For weak excitation, only spontaneous emission (o) is found but above threshold the 

emitted power rapidly increases (●). The external laser threshold is 25 mW, corresponding to 

an internal threshold of 25 W/cm 2 . At 1.2 W excitation, the emitted cw power is 4.8 mW, 

which is the highest value reported for any infrared cw VCSEL. The inset of Fig. 2 (a) shows 

the emitted pulse peak power as a function of pump power, in which case a peak output power 

as high as 23 W was achieved. Figure 2(b) shows the temperature dependent emission for a 

constant 130 mW pump power. As the temperature increases, the spontaneous PbSe emission 

shifts closer to the cavity resonance mode and thus emitted intensity is actually enhanced. At 

30 K, the spontaneous emission coincides with the cavity resonance, resulting in best laser 

performance. At higher temperatures, the spontaneous emission shifts above the cavity mode 

and thus, the laser emission is quenched. The laser wavelength can be tuned by +0.058 

meV/K or –2.1 nm/K as found for a 100 K VCSEL emitting at 6.7 µm. This is substantially 

larger as compared to that of III-V quantum cascade lasers. The emission can also be tuned by 

applying external magnetic fields [3]. The beam divergence is extremely narrow (below 1°). 

Because the operation temperatures up to now are only limited by the pump laser wavelength, 

already a few changes in the laser structure and the use of other pump sources are expected to 

lead to higher cw-laser operation temperatures. 

References 

1. J. Fürst, T. Schwarzl, M. Böberl, H. Pascher, G. Springholz W. Heiß “Continuous-wave emission from midinfrared 

IV–VI vertical-cavity surface-emitting lasers“ Appl. Phys. Lett. 84, 3268 (2004). 

2. T. Schwarzl, G. Springholz, M. Böberl, E. Kaufmann, J. Roither, W. Heiss, J. Fürst, and H. Pascher, 

“Emission properties of 6.7 µm continuous-wave PbSe-based vertical-cavity surface-emitting lasers 

operating up to 100 K“ Appl. Phys. Lett. 86, 031102 (2005). 

3. J. Fürst, H. Pascher, T. Schwarzl, G. Springholz, M. Böberl, G. Bauer, W. Heiss “Magnetic field tunable circularly 

polarized emission from mid-infrared vertical emitting lasers” Appl. Phys. Lett. 86, 021100 (2005). 


1 

Experimentalphysik I, Universität Bayreuth, Universitätsstrasse 30, D-95447 Bayreuth, Germany. 

Funding: FWF and GME 

Corresponding Author: gunther.springholz@jku.at 

0.4 

0.0


Resonator Fabrication for Cavity Enhanced, Tunable Si/Ge Quantum 

Cascade Detectors 

M. Grydlik, P. Rauter, T. Fromherz, G. Bauer, L. Diehl 1 , C. Falub 1 , G. Dehlinger 1 , H. Sigg 1 , 

D. Grützmacher 1 , G. Isella 2 

Infrared detection employing optical transitions in quantum wells has attracted a lot of research 

interest in the past several years. Due to the design freedom a variety of detector figures 

like for example the spectral region of sensitivity, the response time, the detector noise 

etc. can be adjusted over a large parameter range and optimized detector performance can be 

achieved for several areas of applications. In a recent work on SiGe QWIPs, we have demonstrated 

that in addition a large wavelength tunability can be achieved by employing the injector 

concept originally developed for quantum cascade electro-luminescence and laser structures 

[1]. The detectivity of these tunable SiGe QWIPs at 77K is approximately 1.5 x 10 9 

cmHz 0.5 /W, typically 1-2 orders of magnitude smaller than the detectivity of group III-V 

based devices. One concept to increase the detectivity of SiGe QWIPs in a narrow detection 

bandwidth consists of integrating the QWIP into a vertical resonator. Since for QWIPs based 

on SiGe cascade structures, an extremely large tuning range from for example 200 meV to 

400 meV was demonstrated [1], the integration of this novel detectors into a properly designed 

vertical cavity will allow resonator enhanced detection for 2 narrow bands at wavelengths 

λ �and 2λ that can be addressed by the externally applied voltage. 

For integrating a tunable QWIP into a vertical cavity resonator, nominally the same QW 

sequence as described in Ref. [1] have been grown on a SOI substrate by low temperature (T= 

300°C) solid source MBE and processed into detectors. A similar tunability as reported previously 

[1] for detectors grown on Si substrate was achieved with these SOI based structures. 

For fabricating vertical cavity resonators, openings aligned to the detector mesas have to be 

etched from the backside of the sample trough the substrate. The buried oxide layer of the SOI 

substrate is used as an etch-stop. After removing the remaining SiO2 layer by an HF etch, a 

free standing film consisting of the detector QW sequences results. On the top and bottom 

side of this detector film, broadband, high-reflectivity metal or bragg – mirrors will be deposited 

that finally form the resonator. 

From the previous paragraph it is clear, that the choice of a proper etchant is crucial for 

successful resonator fabrication. In our work, TMAH (Tetramethylammonium Hydroxide) at 

90 °C was used as etchant for the following reasons: a) TMAH has reasonably large etchrate 

(30 µm/h) for the Si (001) lattice plane that allows to etch free the buried oxide layer of a 

thinned SOI substrate (200 µm) in approximately 7 h. b) In addition, the TMAH etch rate for 

Si (111) lattice planes is approximately an order of magnitude smaller than in (001) direction. 

Therefore, TMAH etch grooves are bound by (111) planes and negligible underetching of the 

etchmask occurs. c) The etchrate of TMAH for thermally grown oxide is virtually vanishing. 

Therefore the etching process is effectively stopped by the 200 nm thick buried oxide of the 

SOI substrate. Even after a 2 h long over-etching the exposed SiO2 layer showed no indication 

of an etch attack and remained optically flat. d) TMAH is compatible with the standard Si 

technology as it is contained in most of the photoresist developers. 

For the long etch times required to etch from the wafer backside to the buried SiO2, an etch 

mask with high resistance against TMAH is required. In standard Si MEM technology, a 

structured Si3N4 layer deposited by LPCVD at approximately 900°C is commonly used as 

mask for long TMAH etches. However, due to the high deposition temperature necessary for 

the LPCVD process, this mask material can not be used for samples with QWIP structures 

grown on the wafer frontside. On the other hand, a 300 nm thick Si3N4 deposited at lower 

temperatures (250 °C) in a plasma enhanced CVD (PECVD) process was destroyed by the


TMAH etch after approximately 100 nm etch depth. Increasing the thickness of the Si3N4 to 

400 nm and 500 nm did not improve the results most probably due to increased number of 

strain induced cracks in the thicker the Si3N4 layers. 

The best results were obtained by a mask consisting of a double layer of Si3N4 (200 nm) 

and the spin-on polymer BCB (Bencocyclobutene, Dow Chemicals brand name: “Cyclotene” 

[2]) with a thickness of 6-8 µm. BCB can be structured by reactive ion etching in a mixed O2 

and CF4 plasma. The Si3N4 layer acts as an adhesion promoter for the BCB film. With this 

mask and a 10 h long TMAH etch, free standing Si membranes could be produced on a testwafer 

consisting of a Si layer grown on an SOI substrate instead of the Si/Ge QWIP structure. 

Electron and optical microscope pictures of the membrane are shown in Figs. 1 a-d. In the optical 

microscope (Figs. 1a, b) no surface roughness of the membrane and the (111) sidewalls 

are visible. The sample shown in Figs 1 a,b was illuminated from the backside resulting in a 

bright appearance of the Si membranes, indicating that the membranes are transparent in the 

visible spectral region due to their small thicknesses. Also the electron microscope pictures 

(Figs. 1 c,d) do not show significant surface roughness of the membranes and the sidewalls. 

The etchmask shown in Fig. 1 d is evidently not attacked by the TMAH etch and only a small 

underetching due to the non-vanishing etchrate in (111) direction is shown. Infrared transmission 

through a Si membrane was measured with an infrared microscope. The transmission 

spectrum plotted in Fig.1e shows strong Fabry-Perot oscillations with a periodicity corresponding 

to a membrane thickness of 1.42 µm.In future work, the linewidth and of these oscillation 

will be decreased by increasing the cavity Q-factor with high-reflectivity broadband 

mirrors deposited on the membrane surfaces. 

Fig.1: Results obtained by visible (a,b), electron (c,d) and infrared microscope (e) experiments revealing an 

optically flat Si membrane with thickness of 1.42 µm fabricated by the process described in the text. 

References 

1. P. Rauter, T.Fromherz, G. Bauer,L. Diehl, G. Dehlinger, H. Sigg, D. Grützmacher, H. Schneider, “Voltage 

tuneable, two-band MIR detection based on Si/SiGe quantum cascade injector structures“, Appl. Phys. Lett. 

83, 3879-3881 (2003). 

2. http://www.dow.com/cyclotene/ 


1 

Laboratory for Micro- and Nanotechnology, Paul-Scherrer Institute, CH-5232 Villigen PSI, Switzerland; 

2 

Politecnico di Milano, 22110 Como, Italy 

Funding: BMVIT (Proj. Nr. GZ 604000/14-III/I5/2003), EC project SHINE (IST-2001-38035), GME. 

Corresponding Author: Thomas.Fromherz@jku.at


Lateral Quantum Dots in High-Mobility Heterostructures 

G. Pillwein, T. Berer, G. Brunthaler, F. Schäffler, and G. Strasser 1 

Lateral quantum dots are discussed as a promising option to realize the quantum entanglement 

necessary for quantum computation [1]. We have fabricated single quantum dot devices in the 

two-dimensional electron gas (2DEG) of both GaAs/AlGaAs and Si/SiGe heterojunctions. 

These devices are the basic building blocks of more complex structures (e.g. [2]), which we 

plan to investigate in the near future. 

The technology developed for the GaAs structures has been adapted to Si/SiGe based lateral 

quantum dots. Recently, several lateral quantum dots in silicon/silicon-germanium heterostructures 

have been reported e.g. [3]. However, none of these were achieved by the classical 

split-gate technique that is necessary for the coupling of quantum dots and for high integration. 

Both the GaAs/AlGaAs and Si/SiGe high mobility modulation doped heterostructures were 

grown by MBE, in the cleanrooms of TU Vienna and JKU Linz respectively. The 2DEG in 

these samples is typically situated around 80 nm below the surface. 

The electrical properties of the 2DEG were determined by quantum Hall effect and SdH 

measurements. The GaAs samples had a maximum mobility of 2x10 6 cm 2 /Vs at a carrier density 

of typically 2x10 11 cm -2 , the SiGe samples showed an electron mobility of 150000 cm²/Vs 

at an electron density of 3.2 x 10 11 cm -2 

Further processing of the samples was done in the cleanroom in Linz. Ohmic contacts, mesas 

and connection structures for the gates were structured by optical lithography. The split 

gate structures, which define the actual quantum dot, were written by e-beam lithography and 

defined by liftoff of Cr/Au (Pd) for GaAs (SiGe). Typical structures are shown in Fig. 1, 

where the top center gate electrode acts as a plunger gate. 

Fig.1: Scanning electron micrographs of a) the Cr/Au top gates on a GaAs/AlGaAs sample 

and b) the Pd split gates on a Si/SiGe sample. The pitch between the upper gates is 185nm 

When a negative voltage is applied to the gates the 2DEG beneath is depleted and the dot 

is defined in the central area. By varying the plunger gate voltage, the energy levels inside the 

dot can be moved into and out of resonance with the Fermi level in the leads. The conductance 

will increase, when the energies are aligned and decrease in between, forming the socalled 

Coulomb oscillations. If a large DC bias is applied at the source drain contacts the 

blockade can be overcome and excited energy states of the quantum dot can be probed. 

By measuring the conductance versus both the plunger gate voltage VG and the source 

drain voltage VSD, we obtain the so-called quantum dot spectrum. It gives access to a lot of 

information about the quantum dot. Such a measurement in the SiGe structure is shown in 

figure 2a below.


Fig.2: Differential conductance of the a) SiGe and b) GaAs quantum dot as a function of gate 

voltage and applied dc source-drain voltage c) reproducible conductance fluctuations. 

From the size and shape of the rhombic regions (indicated by lines in Fig 2b) we can obtain 

electrical properties such as capacitances of the gates and leads with respect to the dot. By 

analyzing the measured Coulomb diamonds for the SiGe device (Fig 2a), we estimated the 

gate and the source capacity to be 6.4aF and 30aF respectively and the total dot capacity to be 

65aF. Therefore the dot diameter is approximately 160nm, which corresponds to less than 70 

electrons in the dot. A measurement of a comparable GaAs quantum dot is shown in Figure 

2b. In a few of the investigated GaAs samples we have additionally observed conductance 

fluctuations superimposed upon the usual Coulomb oscillations. What at a first glance looked 

like random noise, turned out to be a reproducible fluctuation on a very small gate voltage 

scale, which was preserved over several sweeps in both directions (see figure 2c). 

In summary one can say that the experience which was at first gathered on dots in the 

GaAs system was very valuable in order to show that SET functionality can also be achieved 

in modulation-doped Si/SiGe heterostructures using a standard split-gate approach, which in 

fact was long doubted in the SiGe community. 

References 

1. D. Loss, D.P. DiVincenzo: “Quantum computation with quantum dots”, Phys. Rev. A 57, 1998, 120 – 126 

2. J. Elzerman et al.: “Few-electron quantum dot circuit with integrated charge read out“, Phys. Rev. B 67, 

2003, 161308-1 – 161308-4 

3. A. Notargiacomo et al: “Single-electron transistor based on modulation-doped SiGe heterostructures”, APL, 

83, 2003, 302 – 304 


1 

Institut für Festkörperelektronik TU Vienna, Austria 

Funding 

FWF (P16160 and P16223-N08) 

Corresponding Author: georg.pillwein@jku.at


Surface evolution and shape transitions of self-assembled PbSe 

quantum dots during overgrowth 

L. Abtin, A. Raab, V. Holy 1 and G. Springholz 

Self-assembled semiconductor quantum dots synthesized via the Stranski-Krastanow 

growth mode are of great interest for opto-electronic devices. For such applications, quantum 

dots have to be embedded in a higher band gap matrix material in order to preserve their excellent 

optical and electronic properties. For InAs as well as SiGe quantum dots, however, a 

strong intermixing between the dot and matrix material has been observed during overgrowth, 

which is accompanied by marked changes in the dot sizes and shapes. Due to the strong dependence 

of the electronic properties of the dots on their geometry and chemical composition, 

clearly, a detailed knowledge about these shape transformations is of crucial importance. 

In the present work, we have investigated the morphological evolution of self-assembled 

PbSe quantum dots grown by MBE onto -5.4 % lattice-mismatched PbTe (111) [1]. Due to 

the narrow band gap of PbSe, these dots are of interest for mid-infrared devices such as lasers 

and detectors [2]. PbSe dot exhibit a well-defined pyramidal shape with triangular base and 

(100) side facets [1]. For the overgrowth studies, a series of samples was prepared in which 

the PbSe dots were overgrown with PbTe or Pb1-xEuxTe cap layers with different Eu concentration 

and cap layer thicknesses. Figure 1 shows the evolution of the surface structure during 

the capping of the dots revealed by AFM and STM. Clearly, a rapid shrinking of the dot 

height is observed such that the dots are completely planarized already after 40 Å PbTe cap 

layer thickness. On the other hand, no significant increase in the base width occurs such that 

the total volume of the dots shrinks during the capping process. This means that the top part 

of the dot pyramids is dissolved and homogenously distributed in the surrounding matrix material. 

After complete surface planarization, pronounced surface depressions of about 2 Å 

Figure 1: AFM (a) and STM (b)-(f) surface images of 5 ML PbSe self-assembled quantum dots covered 

with different PbTe cap layer thicknesses: (a) uncovered dots with an average height of 105 Å, and dots 

after 20, 30, 40, 60, 80 and 120 Å PbTe captions. Clearly, the overgrowth leads to a rapid shrinking of the 

dots so that the surface is completely planarized already after 40 Å cap layer thickness. Due to the strain 

fields of the buried dots, weak surface depression are observed on the planarized surface (black spots). 

These correspond to the lattice contraction around the subsurface tensily strained PbSe dots.


Figure 2: RHEED patterns of (a) 3D surface with PbSe quantum dots before overgrowth and (b) after 

complete overgrowth with Pb1-xEuxTe spacer layer. (c) Normalized intensity of (224) spot as a function 

of Pb1-xEuxTe spacer thickness for x=0, 0.03, 0.05, 0.08, 0.1 and 0.13. Each curve has a relative offset of 

20 for clarity. Right hand side: effective dot height of buried dots extracted from RHEED (■) as well as 

AFM (○) investigations plotted as a function of Eu content of the cap layer. The dashed line indicates 

the initial dot height of 105 Å before overgrowth. 

are observed in the STM images. This arises from the lattice contraction around the tensily 

strained PbSe dots below the surface. As the cap layer thickness increases, the amplitude of 

these surface depressions continuously decreases (see Fig. 1) due to the decay of the stress 

fields. From the fitting of the measured STM surface profiles using a numerical strain field 

simulation, the buried dot shape can be reconstructed, indicating that the dots assume a truncated 

pyramidal shape during overgrowth. Figure 2 shows the RHEED patterns and the intensity 

evolution of the 3D diffraction spot as a function of cap layer thickness for several different 

Pb1-xEuxTe cap layer compositions. Clearly, in all cases a rapid replanarisation takes place, 

but the thickness required for planarization strongly increases as a function of the Eu content. 

As a consequence, the incorporation of Eu in the cap layer drastically suppresses the dissolution 

of the PbSe islands such that for sufficiently high Eu concentrations the original pyramidal 

dot shape can be preserved during overgrowth. 

References 

1. G. Springholz, V. Holy, M. Pinczolits, and G. Bauer, “Self-organized growth of three-dimensional quantum 

dot crystals with fcc-like stacking and tunable lattice constant” Science 282, 734 (1998). 

2. G. Springholz, T. Schwarzl, W. Heiss, G. Bauer, M. Aigle, H. Pascher, and I. Vavra „Mid-infrared surfaceemitting 

PbSe/PbEuTe quantum dot lasers“, Appl. Phys. Lett. 79, 1225 (2001). 


1 

V. Holy, Department of Electronic Structures, Faculty of Mathematics and Physics, Charles University, 

12116 Prague, Czech Republic 

Funding 

FWFand GME. 

Corresponding Author: gunther.springholz@jku.at 

d)


Self-Organization of Ripples and Islands with SiGe-MBE 

G. Chen, H. Lichtenberger, G. Bauer, and F. Schäffler 

We explored two methods to obtain laterally ordered Ge/Si quantum dot arrays. For the first 

we exploit the two independent growth instabilities of the SiGe/Si(001) hetero-system, 

namely kinetic step bunching and Stranski-Krastanov (SK) island growth, to implement a 

two-stage growth scheme for the fabrication of long-range ordered SiGe islands. The second 

approach is to deposit Ge/SiGe onto prepatterned Si-substrates, which are prepared via lithography 

and subsequent reactive ion etching (RIE). It results in perfectly ordered, 2D dot arrays 

that can be extended into 3D by strain-ordering of a Ge-dot superlattice. 

The detailed understanding of homoepitaxial step bunching on Si(001) allowed us to tailor 

the period and height of the bunches by controlling substrate miscut, growth temperature, 

deposition rate and layer thickness. This way, homoepitaxial layers with ripple periods of 

100±10nm were prepared on Si(001) substrates with 4° miscut along [110] (see Annual Report 

2003, p.14). These were then employed as templates for the ordering of SiGe or Ge dots 

grown in the strain-driven Stranski-Krastanov mode. When the period length of the template 

complies with the mean spacing of the dots, only one dot row fits into one period (Fig.1). 

Fig. 1: a─b) Self-organized SiGe dots on a rippled 1000Å Si-buffer template with the 50Å 

Si0.55Ge0.45 epilayer deposited @ 625°C; c) Surface orientation maps derived from Fig.1b. 

The dots show preferentially {1 0 5} facets (inner circle). d) Fast Fourier Transform of 

Fig.1a, revealing rectangular, face-centered ordering of the dots. 

We could show that the dots then nucleate at the step bunches, where the energetically favorable 

{1 0 5} facets of the dots are most easily created by step-meandering [1-2]. Considering 

growth further away from thermal equilibrium, the Si0.55Ge0.45 film deposited at 425°C 

does not completely disintegrate into individual islands, but reveals how and where island nucleation 

commences: Upon SiGe deposition the flanks of the step bunches are converted into 

a zigzag train of adjacent (1 0 5) and (0 1 5) facets. The originally smooth flanks match quite 

well the slope of the [5 5 1] intersection line between two adjacent {1 0 5} facets and thus can 

easily be converted into a {1 0 5} faceted SiGe ridge structure, which is perpendicular to the 

step-bunches. This is a step-meandering instability induced by strain and the low-energy {1 0 

5} facets of SiGe on Si(001). It marks the transition from conformal Si/SiGe epilayer growth 

to strain-driven, ordered 3D-growth which is observed at 625°C for the Si0.55Ge0.45 epi-layer 

(Fig.1). This leads to a fair degree of 2D rectangular, face-centered ordering of the SiGe dots 

(Fig.1d) in an approach that employs self-organization mechanisms only [1-3].


To realize perfectly ordered SiGe and Ge dots in 2D and 3D, we used lithographically defined 

pit arrays. For small enough periods, only one dot per unit cell is created, which nucleates 

at the lowest point of the pit (Fig.2). 

Fig. 2: 3D-AFM representations of a perfect 2D array of self-organized Ge with a 

periodicity of 350 nm on a Si template defined by lithography and reactive ion etching. 

XTEM images reveal that the nucleation site is defined by the intersection of neighboring 

facets, which form during Si buffer layer deposition on the nano-structured templates. Thus, 

by combining nano-structuring with self-organized growth, arbitrarily large areas of perfectly 

ordered 2D SiGe and Ge dot arrays can be implemented [4]. On this base we also realized 

perfect 3D Ge dot arrays by additionally exploiting the strain-driven vertical ordering of Ge 

dots in a Si/Ge dot super-lattice. 

Lithographically defined ordering of SiGe and Ge dots fulfills an essential precondition for 

all but the must elemental applications of self-organized dots, namely their addressability. 

Vertical stacking of such arrays provides the option to use the topmost dot layer as a selfaligned 

mask for selective ion implantation [5]. 

References 

1. H. Lichtenberger, M. Mühlberger, and F. Schäffler, “Ordering of Si0.55Ge0.45 Islands on Vicinal Si(001) 

Substrates: The Interplay between Kinetic Step Bunching and Strain-Driven Island Growth”, Appl. Phys. 

Lett. 86, 131919 (2005) 

2. J.-H. Zhu, K. Brunner, and G. Abstreiter, “Two-dimensional ordering of self-assembled Ge islands on 

vicinal Si(001) surfaces with regular ripples”, Appl. Phys. Lett. 73, 620 (1998). 

3. C. Teichert, “Self-organization of nanostructures in semiconductor heteroepitaxy”, Phys. Rep. 365, 335 

(2002). 

4. Z. Zhong, A. Halilovic, T. Fromherz, F. Schäffler, G. Bauer, “Two-dimensional periodic positioning of selfassembled 

Ge islands on prepatterned Si(001) substrates”, Appl. Phys. Lett. 82, 4779 (2003). 

5. Z. Zhong, G. Chen, J. Stangl, Th. Fromherz, F. Schäffler, G. Bauer, “Two-dimensional lateral ordering of 

self-assembled Ge islands on patterned substrates”, Physica E 21, 588 (2004). 

Funding 

FWF, INTAS, GME. 

Corresponding Author: herbert.lichtenberger@jku.at


Transmission Electron Microscopy (TEM) of Nanostructures 

W. Schwinger, D. Pachinger, G .Hesser, F. Schäffler 

Transmission Electron Microscopy is available in the Technical Service Unit (TSE) of the 

Technical/Natural Science faculty (TNF). The scientific responsibility for TEM operation lies 

with the Institute for Semiconductor Physics, which also provides service for other groups of 

the faculty. Available equipment comprises a 200keV Jeol 2011 FasTem with a Gatan MultiScan 

CCD camera and an EDX system, as well as standard preparation facilities. 

Like in the preceding years, a large number of different materials were investigated in 

2004 by TEM. In the following some examples will be shown to demonstrate the scope and 

expertise available in this vital field of nanoanalytics. 

1. SiGe Quantum Wells 

Figure 1 shows a cross sectional TEM image of a Si1-xGex double quantum well embedded 

into a SiGe matrix. This type of samples was designed for spintronic applications, which are 

especially promising in this heterosystem because of the unrivalled spin life- and coherence 

times. Self-consistent simulations were employed to optimize a structure that consists of two 

quantum wells with x=0 and x=0.1, separated by a thin barrier with x=0.15. The sample 

shown in figure 1 is a first attempt to realize such a structure on a relaxed Si0.75Ge0.25 buffer 

layer and with top-sided modulation doping. The low resolution, high-material-contrast image 

in figure 1 clearly reveals the two quantum wells and the thin barrier separating them. The 

insert shows an image of the quantum well section with atomic resolution, demonstrating coherent 

and defect-free MBE growth. 

Fig. 1 Si1-xGex double quantum well structure 

for spintronic applications. High-resolution 

insert shows the absence of lattice defects. 

Fig. 2 CdSe nanocrystals synthesized from a 

chemical solution. Insert shows one of the dots 

with atomic resolution. 

2. Chemically Synthesized Nanocrystals 

Among the schemes developed for the self-organization of nanocrystals and quantum dots, 

chemical synthesis is one of the most straightforward and promising techniques. In this technique, 

nanocrystals are produced in a supersaturated solution that contains, besides the chemi-


cal precursors, organic molecules that cover the surface of the nanocrystals. This organic shell 

keeps the nanocrystals separated in a suitable solvent, and also allows removal or exchange of 

the solvent without aggregation. TEM is the technique of choice for monitoring the size distribution 

of the nanocrystals and the functionality of the organic shell. Figure 2 shows as an 

example CdSe quantum dots with a diameter of about 7 nm. The low-resolution image reveals 

the homogeneous size distribution of these nanocrystals. The inset shows a high resolution 

image of one of the dots. Images were taken at an acceleration voltage of 100 keV to suppress 

electron-induced damage to the nanocrystals. 

3. ZnO on SrTiO3 

The third example is from a collaboration with the Institute for Applied Physics, who prepare 

tilted ZnO films on SrTiO3 substrates by pulsed laser ablation. These piezoelectric films 

are interesting candidates for the excitation of surface acoustic waves in liquids for biological 

applications. Figure 3 shows a high-resolution image of a grain boundary between two ZnO 

domains with different growth orientation. Results like this allowed an almost complete suppression 

of the domain structure by optimizing the substrate orientation and the deposition 

Fig. 3 HRXTEM image of the grain boundary in a 

twinned ZnO film on (110) oriented SrTiO3 

conditions. 1 An example for such an optimized ZnO film is shown in figure 4. 

References: 

1. M.Peruzzi, J.D.Pedarnig, D.Bäuerle, W.Schwinger, F.Schäffler, Applied Physics A 79, 1873 - 1877 (2004) 

2. Z.Zhong, A.Halilovic, H.Lichtenberger, F.Schäffler, G.Bauer, Physica E 23, 243 - 247 (2004) 

3. E.Arici, H.Hoppe, F.Schäffler, D.Meissner, M.A.Malik, N.S.Sariciftci, Thin Solid Films 451, 612 (2004) 

Cooperations: 

J. Pedarnig, M. Peruzzi, Institut für Angewandte Physik, Universität Linz 

E.Arici, H. Hoppe, M. Drees, Institut für Organische Solarzellen, Universität Linz 

K.Lischka, Institut für Physik und Technologie Optoelektronischer Halbleiter, Universität Paderborn 

E+E - Elektronik GmbH., A-4209 Engerwitzdorf 

LUMICS GmbH, D-12489 Berlin 

Funding: FFF, FWF 

Corresponding Author: Friedrich.Schaffler@jku.at 

Fig. 4 Similar to Fig. 3, but on (001) SrTiO3 with 25° 

tilt. Twinnig is now widely suppressed.


Epitaxially grown GaP/GaAs1-xPx/GaP double heterostructure nanowires 

studied by x-ray diffraction 

J. Stangl, G. Bauer, C.P.T Svensson 1 , W Seifert 1 , M Larsson 2 , L Samuelson 1 

In a collaboration with the University of Lund, Sweden, we investigated epitaxially grown 

GaP/GaAsP/GaP double heterostructure nanowires using high-resolution x-ray diffraction [1]. 

Such nanowires are of interest due to their electrical and optoelectronic properties, which 

make them promising as building blocks in future nanoscale devices. During recent years, several 

single nanowire devices have already been demonstrated, including single-electron transistor 

[2], resonant tunnelling diode [3], light emitting diode [4,5], photo detector [6], laser [7] 

and nano-sensors for detection of biological and chemical species [8]. 

Fig. 1: SEM image of GaP/GaAsP/GaP nanowires grown by MOVPE. 

The wires investigated here have been grown by metal organic vapor phase epitaxy 

(MOVPE) on GaP(111)B. Figure 1 shows an SEM image of the resulting wires. The wires are 

grown using 40 nm large Au particles at the cleaned GaP surface as seeds for wire growth. 

PH3 and tri-methyl-gallium (TMG) are used to grow the GaP segments of the wires. To introduce 

a segment of GaAsP, additionally AsH3 is introduced into the growth chamber. Using 

different PH3 to AsH3 flow ratios during growth of the GaAs1-xPx segment, the composition of 

the segment can be varied, making it feasible to tune the wavelength of light emitted from the 

wire. Photoluminescence from the wires was observed by scratching them off the substrate 

and deposit them on a Au-patterned Si/SiO2 substrate. Different luminescence wavelengths 

have been observed for different arsine to phosphine ratios. If interpreted as PL from completely 

relaxed material, the PL energies in the range of 1.60 to 1.72 eV correspond to As 

compositions of the GaAsP segments between 85% and 76%, respectively. 

In order to obtain independent information on the strain state and composition, as well as 

on the crystallinity of the nanowires, we performed high-resolution x-ray diffraction at beamline 

BW2 at the Hasylab in Hamburg, Germany. Figure 2(a) shows the radial (ω-2θ) scan around 

the (111) Bragg reflection of the sample. The sharp peak in the centre is originating 

from the GaP substrate. The leftmost peak is due to GaAsP, which is a first proof that the wires 

are really grown epitaxially on tht substrate. Its position corresponds to a lattice parameter 

aL = 5.60 Å of the GaAsP part in growth direction. The strain state of the GaAsP was obtained 

from a reciprocal space map around the (224) Bragg reflection shown in Fig. 2(b). The peak 

due to the GaAsP needles is rather faint, due to lateral inhomogeneities on the sample. Nevertheless 

we obtain a complete strain relaxationof the GaAsP segment. With bulk lattice parameters 

of aGaP = 5.451 Å and aGaAs = 5.654 Å, and considering the full relaxation of the


GaAsP part of the needles, an As content of about 75% is derived for the GaAsP part of the 

wires, in good agreement with the PL results. The small peaks on the left side of the GaP peak 

in Fig. 2(a) hint on As incorporation in parts of the GaP segments of the wires. 

intensity (arb.u.) 

a) 5.35 

5.30 

b) 

-1 

Qz (Å ) 

-1 

Qz (Å ) 

5.25 

5.20 

5.15 

5.10 

1.7 1.8 1.9 2 

-1 

Qx (Å ) 

Fig. 2: (a) High-resolution x-ray scan along Qz around the (111) Bragg reflection. (b) 

Reciprocal space map around the asymmetrical (224) Bragg reflection. 

GaP 

GaAs P 

0.75 0.25 

References 

1. C.P.T. Svensson, W. Seifert, M. Larsson, J. Stangl, G. Bauer, L. Samuelson, Nanotechnology 16, 936 

(2005). 

2. C. Thelander, T. Mårtensson, M.T. Björk, B.J. Ohlsson, M.W. Larsson, L.R. Wallenberg, L. Samuelson, 

Appl. Phys. Lett. 83, 2052 (2003). 

3. M.T. Björk, B.J. Ohlsson, C. Thelander, A.I. Persson, K. Deppert, L.R. Wallenberg, L. Samuelson, Appl. 

Phys. Lett. 81, 4458 (2002). 

4. M.S. Gudiksen, L.J. Lauhon, J. Wang, D.C. Smith, C.M. Lieber, Nature 405, 617 (2002). 

5. Q. Fang, Y. Li, S. Gradečak, D. Wang, C.J. Barrelet, C.M. Lieber, Nanoletters 4, 1975 (2004). 

6. J. Wang, M.S. Gudiksen, X. Duan, Y. Cui, C.M. Lieber, Science 293, 1455 (2001). 

7. X. Duan, Y. Huang, R. Agarwal, C. M. Lieber, Nature 421, 241 (2003). 

8. Y. Cui, Q. Wei, H. Park, C.M. Lieber, Science 293, 1289 (2001). 


1 

Solid State Physics/The Nanometer Structure Consortium, Lund University, Sweden. 

2 

Materials Chemistry/nCHREM, Lund University, PO Box 124, SE-221 00 Lund, Sweden 

Funding 

EU, FWF, BMWV 

Corresponding Author: julian.stangl@jku.at


X-Ray Diffraction from a SiGe Island Quasicrystal 

J. Stangl, J. Novak, E. Wintersberger, V. Holý 1 , G. Bauer 

Self-assembled island growth in the Stranski-Krastanow mode is a well-established method. 

An improvement of the size homogeneity can be achieved by growing islands in regular 2D 

arrays [1-5]. Such an array can be extended into a 3D island crystal by stacking island layers 

separated by spacer layers [6,7]. Shape and size of the islands as well as their chemical composition 

undergo substantial changes during capping mainly due to interdiffusion with the 

spacer material. We used coplanar high-angle XRD to investigate the size and the chemical 

composition of Ge/Si islands in a 3D island crystal. The evaluation of the experimental data 

was based on calculations of diffusely scattered intensity for a model island. For the calculations 

of the elastic strain fields caused by lattice mismatch between Si and Ge, we refined an 

analytical solution of continuum elasticity equations [8-10]. 

The investigated sample was grown by solid-source molecular beam epitaxy on Si(001), 

which was prepatterned with a square grid of pits using electron beam lithog-raphy and reactive 

ion etching. The pit grid is oriented along 〈110〉 directions and has a period of 400 nm. 

The size of the patterned area is 0.5×0.5 mm 2 . After growth of a 150 nm thick Si buffer layer, 

further deposition of 6 ML of Ge at 700°C resulted in 2D ordered islands, with one island per 

pit. After depositing 30 nm of Si, 12 double-layers of Ge islands and Si spacer layers of about 

25 nm were deposited at 650°C. The topmost island layer was left uncapped for AFM investigations. 

A nearly perfect 3D island crystal was produced in this way. Details on growth and 

atomic force microscopy (AFM) images of the topmost island layer are shown in Ref. 7. The 

aspect ratio of the uncapped island sidewalls height/width = 0.2 corresponds to {105} sidewall 

orientation, which is characteristic for pyramidal islands. 

The measurements were carried out at beamline ID10B at the European Synchrotron Radiation 

Facility (ESRF), Grenoble, at a wavelength of 1.547 Å. Diffusely scattered intensity 

around the symmetrical (004) and asymmetrical (224) substrate lattice points was measured. 

A large number of lateral satellite peaks due to the preiodic island arrangement was observed. 

Figure 1(a,c) shows the integrated intensity of these satellites as a funtion of satellite order 

and of the vertical momentum transfer Qz relative to the substrate. 

For the simulations of scattered intensity we used kinematical scattering theory. The expressions 

used involve the displacement field in the sample, which we calculated by means of 

an analytic solution of the elasticity equations. We assume that the islands in each layer form 

a perfect 2D lattice and that they are perfectly stacked above each other. Additionally, the 

size, shape, and chemical composition of all islands in the 3D island crystal is assumed to be 

identical. We neglected the uncapped island layer on top of the sample, but rather assume a 

flat sample surface. In coplanar diffraction geometry, the existence of the uncapped island 

layer has no significant influence on the scattered intensity. For the island shape we assumed 

a truncated cone, characterized by its bottom and top radii Rbot and Rtop, and the height hi. The 

Ge content xi was assumed to be constant within the islands. Details on the strain calculations 

can be found in Ref. 11. Using these results, the scattering pattern is simulated. 

The best fitting results are shown in Fig. 1(b,d) for (004) and (224) reflections, respectively. 

We obtain values of Rbot = 85±10 nm and Rtop = 10±10 nm, hi = 19±4 nm, and for the 

Ge content xi = 40±10%. We obtain an aspect ratio of η = hi/(Rbot-Rtop) = 0.25±0.06, close to 

η = 0.2 of {105} facets typical for Ge pyramids, and different from η = 0.47 of {113} facets 

typical for Ge domes. From the simulations also the lateral (εxx) and vertical (εzz) strains 

within the island stack follow (zero strain corresponds to the non-deformed Si lattice): The


Fig.1: 2D map of the lateral satellite intensities extracted from RSMs measured around the 

(004) (a) and (224) (c) reciprocal lattice points. Simulations of dif-fusely scattered intensity 

for the (004) (b) and (224) (d) diffractions. 

strain field is almost periodic in the vertical direction only in the region from 4 th to 7 th island 

layers, above and below the surface relaxation and influence of the Si substrate destroy the 

periodicity. The maximum lateral strain of εxx = 0.9% is observed in compressed SiGe in the 

top edges of the islands, corresponding to a degree of relaxation of 55% for Si0.6Ge0.4. The 

lateral strain minimum of εxx = −0.5% is observed in compressed Si around the bottom edges 

of the islands. The vertical strain εzz increases in the lateral direction from the center of the 

islands towards their sidewalls. The maximum of εzz = 3.4% is observed in expanded SiGe in 

the bottom edge of the islands, and the minimum of εzz = −2% is observed in compressed Si 

just above the center of the top island facets. 

References 

1. O.G. Schmidt et al., Appl. Phys. Lett. 77, 4139 (2000) 

2. G. Jin, J.L. Liu, K.L. Wang, Appl. Phys. Lett. 76, 3591 (2000) 

3. J. Stangl, V. Holý, G. Bauer, Rev. Mod. Phys. 76, 725 (2004) 

4. Bin Yang, Feng Liu, M.G. Lagally, Phys. Rev. Lett. 92, 25502 (2004) 

5. Zh. Zhong, G. Bauer, Appl. Phys. Lett. 84, 1922 (2004) 

6. G. Springholz, V. Holý, M. Pinczolits, G. Bauer, Science 282, 734 (1998) 

7. Zh. Zhong et al., Physica E 21, 588 (2004) 

8. T. Roch et al., Phys. Rev. B 65, 245324 (2002) 

9. J.H. Li et al., Phys. Rev. B 66, 115312 (2002) 

10. O. Caha et al., J. Appl. Phys. 96, 4833 (2004) 

11. J. Novak et al., submitted to J. Appl. Phys. 


1 

V. Holý, Department of Electronic Structures, Charles University Prague, Czech Republic. 

Funding: FWF, EU, GME, BMWV 

Corresponding Author: julian.stangl@jku.at


X-Ray Investigation of Thick Epitaxial GaAs/InGaAs Layers on Ge 

Pseudosubstrates 

A. Rehman Khan 1 , K Mundboth 1 , J. Stangl 1 , G. Bauer 1 , H. von Känel 2 , A. Fedorov 2 , G. Isella 2 

Successful integration of GaAs-based heterostructures with Si technology has been hindered 

by various limitations such as large lattice mismatch (4.1%) between GaAs and Si, difference 

in their thermal expansion coefficients (~60%), which leads to high threading dislocation densities, 

formation of anti-phase domains (ADPs) due to polar/nonpolar growth, and crack formation 

due to remaining strain in partially relaxed structures [1]. Some of the drawbacks can 

be removed substantially by introducing a Ge buffer layer between the Si substrate and the 

pseudosubstrate which has been recently achieved by the low-energy plasma-enhanced 

chemical vapour deposition (LEPECVD) technique [2]. As GaAs and Ge have only a very 

small lattice mismatch, using a Ge buffer as a virtual substrate will not lead to a large number 

of misfit dislocations at the interface. 

An important factor in such integrations is the thermal strain introduced during cooling 

from growth temperature to ambient temperature. GaAs has a higher thermal expansion coefficient 

than Si, and if a GaAs layer is completely relaxed at growth temperature, it will contract 

during the cooling process by the same amount as the Si substrate, which is less than the 

intrinsic thermal contraction of GaAs (the same is true for Ge and other layers, as all epilayers 

are much thinner than the Si substrate). At lower temperatures the introduction of dislocations, 

their multiplication and glide is hampered, hence the resulting strain is not relieved. 

The aim of the presented work is to address the issue of this thermal strain in a series of 

GaAs/Ge/Si samples fabricated using the most recent concepts of buffer growth and identify 

the optimum growth conditions. In order to reduce 

the thermal strain, an attempt was made to compensate 

it with the strain in an additional InGaAs layer: 

as InGaAs has a larger lattice parameter than GaAs 

and Ge, a pseudomorphic InGaAs layer (with a 

rather low In content of about 1%, depending on the 

layer thicknesses) would exhibit compressive strain 

that can compensate the tensile thermal strain. We 

use x-ray diffraction around symmetrical (004) and 

asymmetrical (115) Bragg reflections in order to assess 

the strain state of the individual layers (Fig. 1). 

The (115) reflection was chosen as the (224) reflection, 

which would allow for a higher in-plane strain 

resolution of the experiment, is not accessible due to 

the high miscut of the samples (~6°). A main result 

of the lattice parameter determination is that while 

all epilayers in all samples are almost completely 

relaxed to their bulk lattice parameters abulk, still the 

in-plane lattice constant a|| is larger than the perpendicular 

lattice constant a⊥, i.e., all layers exhibit tensile 

strain (Table I). From the assumption that all 

Fig. 1: Reciprocal space maps around 

(115) reflection of samples vk67 (a,b), 

and vk69 (c,d). The close-up in (b,d) 

shows the intensities from GaAs, Ge and 

InGaAs layers. 

layers are completely relaxed at growth temperature 

and that during cooling no change in the dislocation 

network occurs, the values of in-plane lattice constants 

a||,thermal follow and from them the in-plane 

strain values ε||,thermal are derived. For most layers,


the experimental strain values are slightly smaller than those estimated theoretically, yet overall 

the thermal strain does very well explain the observed tensile strain values. 

SAMPLE 

vk66 

vk67 

vk68 

vk69 

LAYER 

SiGe 

xGe= 99.6% 

InGaAs 

xIn= 1.3% 

SiGe 

xGe=100% 

InGaAs 

xIn= 2.0% 

GaAs 

SiGe 

xGe= 99.3% 

InGaAs 

xIn= 2.0% 

SiGe 

xGe= 98.8% 

InGaAs 

xIn= 2.2% 

GaAs 

EXPERIMENTAL 

a|| 

5.6677 

5.6654 

5.6679 

5.6676 

5.6592 

5.6639 

5.6683 

5.6629 

5.6673 

5.6622 

LATTICE CONSTANTS (Å) 

a⊥ 

5.6489 

5.6525 

5.6507 

5.6564 

5.6477 

5.6506 

5.6551 

5.6494 

5.6576 

5.6470 

abulk a||,thermal ε|| 

(%) 

5.6570 

5.6586 

5.6579 

5.6616 

5.6535 

5.6563 

5.6614 

5.6551 

5.6624 

5.6535 

5.6662 

5.6659 

5.6672 

5.6689 

5.6608 

5.6655 

5.6687 

5.6643 

5.6697 

5.6608 

0.19 

0.12 

0.18 

0.11 

0.10 

0.13 

0.12 

0.14 

0.09 

INPLANE STRAIN 

ε||,THERMAL 

(%) 

Table1: Results of lattice constants obtained from XRD measurements. The expected strain (εe) has 

been calculated and compared to the experimental (observed) (εo). All of them have been calculated 

with respect to the Si substrate 

It is shown here that the in-plane lattice parameters of the InGaAs layers match quite 

closely to those of the underlying Ge buffers, but the in-plane lattice parameters of the top 

GaAs buffers do not follow that of InGaAs buffers and indicate at least partial relaxation of 

GaAs at growth temperature. Consequently, the concept of introducing non-relaxed InGaAs 

layers was successful only to a certain extent. With reduced In content of InGaAs layers one 

can envision a pseudomorphic GaAs growth as well and hence a complete compensation of 

the tensile thermal strain could be achieved. The presented method based on x-ray diffraction 

analysis is sensitive to measure even these small thermally induced strain values. 

References 

1. J.A. Carlin, et al, “Impact of GaAs buffer thickness on electronic quality of GaAs grown on graded 

Ge/GeSi/Si substrates” Appl. Phys. Lett. 76, 1884 (2000). 

2. C. Rosenblad, H. von Känel, M. Kummer, A. Dommann, and E. Müller “A plasma process for ultrafast 

deposition of SiGe graded buffer layers” Appl. Phys. Lett. 76, 427 (2000). 


1 

Institute of Semiconductor Physics, Johannes Kepler University, A-4040 Linz, Austria. 

2 

INFM and L-NESS Dipartimento di Fisica, Politecnico di Milano, Polo Regionale di Como, Italy. 

Funding 

Higher Education Commission (HEC) Pakistan, FWF Vienna 

Corresponding Author: aaliya.rehman@jku.at 

0.15 

0.16 

0.13 

0.16 

0.13 

0.13 

0.16 

0.13 

0.16 

0.13 

0.13


Metallic state in two-dimensional Si-MOS structures 

B. Lindner, T. Hörmann, G. Pillwein, G. Brunthaler 

The metallic state (MS) in two-dimensional (2D) electronic systems at very low temperatures 

was discovered 10 years ago, but is still not fully understood. Before it was thought that the 

electronic ground state of a 2D system is always insulating due to disturbance by potential 

fluctuations, which always exist. 

We have worked on the field both experimentally and theoretically. Experimentally, the 

density dependence of the effective mass was determined from magnetoconductivity Shubnikov–de 

Haas (SdH) investigations with special assumptions in the analysis. Theoretically, 

the so-called dipol trap model of Altshuler and Maslov [1] was investigated and refined by 

taking additional effects into account. 

Figure 1a shows the SdH measurements on a metal-oxid-semiconductur structure with silicon 

on insulator substrate. Such samples reach also very high electron mobilities. The analysis 

of the temperature (T) dependence of the SdH oscillations allows the determination of the 

effective mass m*. It is expected that m* increases due to renormalization effects towards 

lower electron densities ns. 

A recent theory of Aleiner et al. [2] explains the T-dependence of the resistivity ρ by the 

quantum mechanical interference effect of coherent back scattering of ballistic electrons. By 

taking this theory serious, the two different time constants of momentum relaxation and quantum 

life time have to be different due to different averaging factors. The quantum life time 

was thus estimated from the T-dependence of the momentum relaxation time and used in the 

SdH fitting procedure. As a result, we obtain the weak density dependence of the effective 

mass as shown by blue circles in Fig. 1b, in contrast to the much stronger m*(ns) dependence 

as usually obtained without the special relation between the two different times. 

Fig.1: a) Temperature dependent Shubnikov–de Haas resistance at an electron density of 3.5 

× 10 11 cm -2 . The measurement curves were fitted by taking into account different relations 

between momentum relaxation time and quantum life time. b) Density dependence of the 

effective mass m* as obtained from the fitting. For coherent back scattering (blue circles), 

m* remains at small values even at low densities. 

Our second approach to the MS in 2D was a detailed investigation of the dipole trap model. 

We analytical calculations of [1] were performed with a saddle-point approximation of the 

potential and by making simplified assumption for the electronic ground state and the Fermi 

energy. As we performed detailed numerical computations of ρ(n,T), we were not restricted 

in this way. 

Figure 2a shows the potential shape and the energies near the oxide-silicon interface. The 

trap states above the Fermi energy are empty and thus positively charged whereas the ones


below are filled and neutral. Figure 2b shows the scaling function of the resistivity according 

to our calculations. Interestingly, at high electron densities, ρ approaches constant values towards 

T = 0, whereas at lower densities it goes to zero if no other scattering events except the 

charged traps are taken into account. The two regions are separated by a well defined separatrix 

corresponding to a certain electron density. 

Fig.2: a) Potential shape and energies around oxid-silizium interface. Left hand side shows 

effective potential of traps including the dipol interaction with the screened electrons. Right 

hand side shows conduction band inversion layer with electronic ground state ε0 and wave 

function. b) Temperature dependence of the scaling function of the resistivity for different 

gate voltages at a log-log scale. For low electron densities (upper curves) the resistance 

saturates towards T = 0, whereas for high densities (lower curves) it goes towards zero 

(without additional scattering sources). 

The flexibility of the numerical calculations allows the extension of the model also for trap 

states which are distributed in energy space and have an inhomogeneous spatial dependence. 

If this is take into account, the sharp transition from one regime into the other is smeared out. 

In summary, the interpretation of experimental investigations and model calculations still 

have room for new and realistic assumptions in order to come closer to a thorough description 

of the metallic state and the metal-insulator transition in 2D electron systems. 

References 

1. B.L. Altshuler and D.L. Maslov , “Theory of metal-insulator transition in gated semiconductors”, Phys. 

Rev. Lett. 82, 145 (1999) 

2. G. Zala, B.N. Narozhny, I.L. Aleiner, “Interaction corrections at intermediate temperatures: Longitudinal 

conductivity and kinetic equation”, Phys. Rev. 64, 214204 (2001) 

3. T. Hörmann and G. Brunthaler, “Numerical evaluation of the dipole-scattering model for the metal-insulator 

transition in gated high mobility silicon inversion layers”, cond-mat/0412762 (2004) 


M. Prunnila and J. Ahopelto, VTT Centre for Microelectronics, Tietotie 3, Espoo 02150,Finland. 

Funding 

Work was supported by FWF Project P16160 and "Gesellschaft für Mikroelectronik" (GME). 

Corresponding Author: Gerhard.Brunthaler@jku.at


Electronic structure of self assembled pyramidal PbSe 

quantum dots 

M. Simma, T. Fromherz, G. Bauer 

Recent studies have shown that it is possible to attain three-dimensional (3D) confinement 

of electrons within strained islands of PbSe that formed on the surface of PbEuTe during the 

Stranski-Krastanow growth method. This growth begins with an initial molecular-beamepitaxy 

buffer layer deposition of PbEuTe on a BaF2 substrate followed by a PbSe layer. After 

a critical thickness of 3-4 ML is reached islands of PbSe with a tetrahedral geometry forms 

spontaneously and a thin wetting layer is left under the islands. By overgrowing the PbSe 

quantum dot (QD) layers with PbEuTe layers three dimensional ordering of the QD can be 

achieved [1]. 

For improvement of opto-electronic properties of the QD superlattices the exact knowledge 

of the electronic structure of the PbSe QD is necessary. In our work we calculated the 

energy levels and wavefunctions of the PbSe QD using the envelope function theory within 

the accuracy of a single-band effective-mass model. The Schrödinger equation for this 3D 

problem was solved by iterative extraction-orthogonalization method (IEOM) [2]. The general 

eigenvalue problem is given by 

m m m (1) 

where m is an eigenstate of the operator , and m is the eigenvalue of m . Now one 

creates an function operator F that effectively extracts the lowest eigenvalue basis state 

0 (i.e., the ground state) from an initial guess vector 0 comprised of a mixture of basis 

states. Operating on 0 with F gives 

f 0 

m 

m f m m 0 0 f 0 0 0 

m 1 

f m m 0 (2) 

Clearly, if F decreases with increasing m the first term in Eq. (2) will dominate 

F m and the new basis composition will favor the ground state. Successive applications of 

F m further extract the ground state such that after some number of iterations Ni, the 

high-order contributions become vanishingly small. 

f 

N i 

0 0 f 0 

N i 0 0 (3) 

In addition to the ground state we need a mechanism to maintain the spectrum of higher (excited) 

eigenstates. This is accomplished by creating a set of NE initial guess states 

m and applying the Gram-Schmidt orthogonalization algorithm 

' n n 

n 1 

m 1 

' m ' m n 

' m 

after each iteration of Eq. (2). 

For the quantum-mechanical eigenvalue problem and m become the Hamiltonian H 

and eigenenergy Em, respectively. Furthermore, the form of F we choose is an exponential, 

exp H , where α is chosen to allow an accurate first-order Taylor expansion. 

The exponential operator is first cast into a split-time form which allows independent application 

of the potential- and kinetic-energy fraction in each extraction iteration 

' m 

(4)


exp H exp 

E c r 

2 

exp 

2 m 

2 

2 E c r 

2 

where E c r denotes the confinement potential and the error is due to the general non commutativity 

of the two operators [2]. We solve the Operator in real space due to the non symmetric 

boundary conditions of the pyramidal QD in a rectilinear coordinate system using finite-difference 

for the kinetic energy operator. Furthermore this operator can be separated into 

the three coordinate components x, y, z. Each of the exponential kinetic-energy operators in 

Eq. (5) can therefore be applied independently and cast into Caylay's form 

exp H exp 

1 

2 

4 m 

E c r 

2 

exp 

2 i 1 

x r 1 

2 m 

2 

2 

4 m 

2 exp 

2 

x 

1 

E c r 

2 

(5) 

(6) 

i r (7) 

which is second-order accurate and requires only the inversion of simple tridiagonal matrices. 

In Eq. (6) and (7) 

i r denotes the wavefunction after i applications of the operator H . 

Wei and Zunger [3] determined the VB discontinuity for the PbSe/PbTe interface as 120 

meV. The VB and CB offset are lowered and raised by the same ratio of the PbEuTe alloy 

bandgap shift due to the Eu content. Furthermore strain affects are considered for the band 

discontinuities in the PbSe/PbEuTe superlattices. This leads to a type II band alignment of the 

PbSe QD where only the electrons are confined by the CB potential of 215 meV calculated 

for 6% Eu content. The results obtained with these calculations allow a clear identification of 

the features observed in the photo-current spectra of PbSe QD structures. 

Fig 1: Isosurfaces of electronic wavefunction in PbSe QD. Left: s-states. Right p-states 

Fig. (1) shows isosurfaces of the s- and p-state electron wavefunction of a 140 Å high PbSe 

QD. The energy levels for these states are 85.7 meV and 181 meV, respectively. 

References 

1. G. Springhoz, V. Holy, M. Pinczolits, and G. Bauer, Science 282, 734 (1998) 

2. R. Koslov, H. Tal-Ezer, Chem. Phys Lett. 127, 223 (1986) 

3. S. H. Wei and A. Zunger, Phys. Rev. B. 55, 13605 (1979) 

Funding: FWF P-14684, GME 

Corresponding Author: mathias.simma@jku.at


Magnetic properties of self organized EuSe quantum dots 

R.T. Lechner, G. Springholz, T.U. Schülli, J. Stangl, S. Dhesi, 1 P. Bencok, 1 G. Bauer 

The fabrication of self-organized semiconductor quantum dots has been the subject of intense 

research efforts because these dots exhibit a large variety of interesting electronic and optical 

properties due to the zero-dimensional density of states. On the other hand, only relatively 

few studies have focused on the magnetic properties of magnetic semiconductor nanostructures. 

In this letter, we report on the fabrication of ordered EuSe nanoislands by molecular 

beam epitaxy and the investigation of their morphology and magnetic properties using magnetic 

x-ray circular dichroism in absorption and scattering geometry. EuSe is a classical 

Heisenberg magnet due to the direct and indirect exchange interactions between the spin 7/2 

Eu 2+ ions in the crystal lattice and it shows a variety of magnetic phases, dependent on hydrostatic 

pressure, magnetic field, and temperature [1]. Thus, it is of great interest to study the 

possibilities to tune the magnetic properties via the epitaxial strains [2] as well as the magnetic 

island interaction. 

As a template for the deposition of the EuSe islands we use self-organized PbSe quantum 

dot superlattices, consisting of a periodic PbSe island multilayer separated by PbEuTe spacer 

layers [3-5]. Depending on the thickness of the PbEuTe spacer layer, either a three dimensionally 

ordered vertically aligned hexagonal PbSe dot superlattice is formed, or a trigonal island 

superlattice with fcc-like dot stacking [4,5]. On top of the last PbSe dot layer of the superlattice 

stack, 5 monolayers of EuSe were deposited. As a result two sets of samples with an 

EuSe island base width of about 70 nm and a height of 12 nm (sample A), and a base width of 

50 nm with a height of 10 nm (sample B) are obtained. For the x-ray scattering experiments, 

which were carried out under UHV conditions at the ID08 beamline of the ESRF, Grenoble, 

the EuSe islands were capped with amorphous Se in order to prevent oxidation [6]. This protecting 

layer was desorbed in the UHV set-up at the ESRF beamline, before the scattering experiments 

were performed. 

Fig. 1: (a) 2D-GISAXS reciprocal space map within a scattering plane parallel to the surface of a 

hexagonally ordered EuSe island layer recorded at an x-ray energy of 7 keV. Inset: Anomalous 

GISAXS scattering line scans (cross section of the reciprocal space map) at two different x-ray 

energies at the Eu absorption edge at 1129 eV (squares) and at an x-ray energy slightly below the 

edge at 1125 eV (crosses). (b) X-ray magnetic circular dichroism (XMCD) intensities of the 

correlation peaks of the EuSe islands (arrow in the inset of (a)) plotted as a function of the applied 

external magnetic field (crosses) at T = 9 K and corresponding Brillouin fit (red line).


For resonant grazing incidence small angle x-ray scattering (GISAXS) experiments at energies 

tuned to the Eu-MV absorption edge (Fig 1 a) it was verified that the lateral satellite peaks 

originate from the hexagonally ordered EuSe islands and not from the PbSe island template. 

Using x-ray photon energies at the Eu-MV edge of 1129 eV and at 4eV below we take advantage 

both of the strong Eu resonance and the extreme surface sensitivity. X-ray magnetic circular 

dichroism (XMCD) scattering intensities were measured at the Eu MIV,V edges. The resulting 

magnetization curves at T = 9 K differ significantly for sample A and B (Fig 1b). 

From fits with a Brillouin function [6] we obtain for the sample A with the larger islands a 

value of the magnetic spin moment S = 8, whereas for the smaller islands of sample B a value 

of S = 7/2, as expected for uncoupled Eu spins is obtained. Despite the fact that the phase 

transition temperature to anti-or ferrimagnetic state at T < 5 K was not yet reached, we have 

conclusive evidence for a size dependence of the blocking temperature to super-paramagnetism 

in these strained nanostructures. For 2D EuSe/PbSeTe superlattices in which the in-plane 

lattice constant of the EuSe layers were tuned by adjusting the ternary composition of the 

PbSeTe spacer layers also very pronounced strain effects were found by SQUID magnetization 

measurements [7]. 

References 

1. H. Kepa, G. Springholz, T. M. Giebultowicz, C. F. Majkrzak, P. Kacman, J. Blinowski, S. Holl, H. Krenn 

and G. Bauer, „Magnetic interactions in EuTe epitaxial layers and EuTe/PbTe superlattices“ 

Physical Review B68, 024419 (2003). 

2. T. U. Schülli, R. T. Lechner, J. Stangl, G. Springholz, G. Bauer, M. Sztucki and T. H. Metzger, ”Strain 

determination in multilayers by complementary anomalous x-ray diffraction”, 

Physical Review B 69, 195307-1-8 (2004). 

3. G. Springholz, V. Holy, M. Pinczolits, and G. Bauer, “Self-organized growth of three-dimensional quantum 

dot crystals with fcc-like stacking and tunable lattice constant” Science 282, 734 (1998). 

4. G. Springholz, M. Pinczolits, V. Holy, P. Mayer, G. Bauer, H. H. Kang and L. Salamanca-Riba 

"Tuning of lateral and vertical correlations in self-organized PbSe/PbEuTe quantum dot superlattices" 

Physical Review Letters 84, 4669 (2000). 

5. R.T. Lechner, T. Schülli, V. Holy, G. Springholz, J. Stangl, A. Raab, T. H. Metzger and G. Bauer 

“Ordering parameters of self-organized 3D quantum dot lattices determined by anomalous x-ray 

diffraction“ 

Applied Physics Letters 84, 885-888 (2004). 

6. T. U. Schülli, R. T. Lechner, J. Stangl, G. Springholz, G. Bauer, S. Dhesi, and P. Bencok, ”Soft magnetic xray 

diffraction from ordered EuSe nanoislands” Applied Physics Letters 84, 2661-2663 (2004). 

7. R. T. Lechner, G. Springholz, T. U. Schülli, J. Stangl, T. Schwarzl, and G. Bauer, ”Strain induced changes 

in the magnetic phase diagram of metamagnetic heteroepitaxial EuSe/PbSeTe multilayers”, Physical 

Review Letters 94, 157201-4 (2005). 


1 

European Synchrotron Radiation Facility, BP 220, F-38043 Grenoble Cedex, France 

Funding 

FWF and GME. 

Corresponding Author: gunther.springholz@jku.at

38 Research Reports Part A: Semiconductor Physics Group

Part A: Semiconductor Physics Group: Theses 39 

Diploma and Doctoral Theses 

Diploma theses finished in 2004 

1. Eugen Wintersberger 

“Röntgenbeugung und –reflexion an Si/SiGe/GaAs Hetero- und Nanostrukturen ” 

2. Mathias Simma 

“Photoleitungsuntersuchungen an Quantenpunkten” 

3. Stefan Janecek 

“Simulation of the magnetic order of few-monolayer-(111)-EuTe in oblique magnetic 

fields” 

4. Benjamin Lindner 

“Metall-Isolator-Übergang in zweidimensionalen Siliziumstrukturen” 

Current diploma theses 

1. Martyna Grydlik 

“Si/SiGe resonant cavity enhanced, tunable mid-infrared quantum well detectors.” 

2. Thomas Hörmann 

“Modellrechnungen und Auswertungen zum Metall-Isolator-Übergang in zweidimensionalen 

Halbleiterstrukturen” 

3. Bernhard Mandl 

“Au-free growth and characterization of semiconductor nanostructures“ 

Doctoral thesis finished in 2004 

1. Mag. Rainer T. Lechner 

“Herstellung und Charakterisierung von EuSe- Nanostrukturen” 

Current doctoral theses 

1. M.Sc. Laurel Abtin 

“STM investigation on self-assembled IV-VI semiconductor nanostructures” 

2. Dipl.Ing. Thomas Berer 

“Electronic and spin properties of Si/SiGe heterostructures” 

3. Dipl.Ing. Daniel Gruber 

“Si/SiGe Heterostructure Devices for Spintronic Applications” 

4. Dipl. Phys. Anke Hesse 

“Strukturelle Untersuchungen an Halbleiternanostrukturen” 

5. Dipl.Ing. Herbert Lichtenberger 

“Kinetic and strain-induced self-organization of SiGe heterostructures” 

6. M.Sc. Dmytro Lugovyy 

“Investigation of vertical and lateral ordering in self-organized PbSe quantum dot superlattices”

40 Theses Part A: Semiconductor Physics Group 

7. Mag. Jiri Novak 

“Untersuchung der strukturellen Eigenschaften von Quantenpunkten” 

8. Dipl.Ing. Dietmar Pachinger 

”Fabrication of SiGe Nanostructures for infrared Devices” 

9. Dipl.Ing. Georg Pillwein 

“Elektrische Untersuchungen von Quanteneffekten an Nanostrukturen” 

10. Dipl.Ing. Patrick Rauter 

“SiGe nanostructures for next generation infrared detectors“ 

11. M.Sc. Aaliya Rehman Khan 

“Growth and structural characterisation of Si/SiGe hetero- and nanostructures” 

12. Dipl.Ing. Mathias Simma 

“Photoleitungsuntersuchungen an Quantenpunkten” 

13. Dipl.Ing. Eugen Wintersberger 

“Röntgenbeugung und –reflexion an Si/SiGe/GaAs Hetero- und Nanostrukturen ”

Part A: Semiconductor Physics Group Publications 41 

published 2004 

Publications 

1. C. Schelling, J. Myslivecek, M. Mühlberger, H. Lichtenberger, Z. Zhong, B. Voigtländer, 

G. Bauer, F. Schäffler, "Kinetic and strain-driven growth phenomena on 

Si(001)", phys. stat. sol. (a) 201, 324-328 (2004) / DOI 10.1002/pssa.2003093966. 

2. G. Grabecki, J. Wrobel, T. Dietl, E. Papis, E. Kaminska, A. Piotrowska, A. Ratuszna, 

G. Sprinholz, G. Bauer, "Ballistic transport in PbTe-based nanostructures", Physica E 

20, 236 - 245 (2004). 

3. G. J. Matt, N. S. Sariciftci, T. Fromherz, "Anomalous charge transport behovior of 

Fullerene based diodes", Applied Physics Letters 84, 1570-1572 (2004). 

4. E. Arici, H. Hoppe, F. Schäffler, D. Meissner, M. A. Malik, N.S. Sariciftci, "Hybrid 

solar cells based on inorganic nanoclusters and conjugated polymers", Thin Solid 

Films 451 - 452, 612 - 618 F(2004). 

5. R.T. Lechner, T.U. Schülli, V. Holy, G. Springholz, J. Stangl, A. Raab, G. Bauer, T.H. 

Metzger, "Ordering parameters of self-organized three-dimensional quantum-dot lattices 

determined from anomalous x-ray diffraction", Appl. Phys. Lett. 84, 885-887 

(2004). 

6. Zhenyang Zhong, Gang Chen, J. Stangl, T. Fromherz, F. Schäffler, G. Bauer, "Twodimensional 

lateral ordering of self-assembled Ge islands on patterned substrates", 

Physica E 21, 588-591 (2004). 

7. R. T. Lechner, T. Schülli, V. Holy, J. Stangl, A. Raab, G. Springholz, G. Bauer, "3D 

hexagonal versus trigonal ordering in self-organized PbSe quantum dot superlattices", 

Physica E 21, 611-614 (2004). 

8. Zhenyang Zhong and G. Bauer, "Site-controlled and size-homogeneous Ge islands on 

prepatterned Si (001) substrates", Appl. Phys. Lett. 84, 1922-1924 (2004). 

9. M. Meduna, J. Novak, G. Bauer, V. Holy, C.V. Falub, E. Müller, D. Grützmacher, Y. 

Campidelli, O. Kermarrec, D. Bensahel, "Annealing studies of high Ge composition 

Si/SiGe multilayers", Z. Kristallogr. 219, 195-200 (2004). 

10. S.D. Tsujino, C.V. Falub, E. Müller, M. Scheinert, L. Diehl, U. Gennser, T. Fromherz, 

A. Borak, H. Sigg, D. Grützmacher, Y. Campidelli, O. Kermarrec, D. Bensahel, "Hall 

mobility of narrow Si0.2Ge0.8-Si quantum wells on Si0.5Ge0.5 relaxed buffer substrates", 

Appl. Phys. Lett. 84, 2829-2831 (2004). 

11. J. Fürst, H. Pascher, T. Schwarzl, M. Böberl, G. Springholz, G. Bauer, W. Heiss, 

"Continuous-wave emission from midinfrared IV-VI vertical-cavity surface-emitting 

lasers", Appl. Phys. Lett. 84, 3268-3270 (2004). 

12. T. U. Schülli, R. T. Lechner, J. Stangl, G. Springholz, and G. Bauer, "Soft x-ray magnetic 

scattering from ordered EuSe nanoislands", Appl. Phys. Lett. 84, 2661-2663 


13. V. M. Pudalov, M. E. Gershenson, H. Kojima, G. Brunthaler, G. Bauer, "Are the interaction 

effects responsible for the temperature and magnetic field dependent conductivity 

in Si-MOSFETs?", Phys. Stat. Sol. (b) 241, 47-53 (2004).

42 Publications Part A: Semiconductor Physics Group 

14. G. Brunthaler, B. Lindner, G. Pillwein, S. Griesser, M. Prunnila, J. Ahopelto, "Two- 

Dimensional Metallic State in Silicon-on-Insulator Structures", Physica E 22, 252 – 

255 (2004). 

15. V. M. Pudalov, M. E. Gershenson, H. Kojima, G. Brunthaler, and G. Bauer , "Reply to 

comment of Das Sarma and Hwang", Phys. Rev. Lett. 93, 269704 (2004). 

16. T. Hörmann und G. Brunthaler, "Numerical evaluation of the dipole-scattering model 

for the metal-insulator transition in gated high mobility Silicon inversion layers", 

cond-mat/0412762, p1-5 (2004). 

17. J. Stangl, T. Schülli, H. Metzger, G. Bauer, "Im Inneren von Halbleiternanostrukturen", 

Physik Journal 3, 33-39 (2004). 

18. R. Kirchschlager, W. Heiss, R. T. Lechner, G. Bauer, G. Springholz, "Hysteresis loops 

of the energy band gap and effective g factor up to 18 000 for metamagnetic EuSe epilayers", 

Appl. Phys. Lett. 85, 67-69 (2004). 

19. Zhenyang Zhong, A. Halilovic, H. Lichtenberger, F. Schäffler, G. Bauer, "Growth of 

Ge islands on prepatterned Si (001) substrates", Physica E 23, 243-247 (2004). 

20. H. Lichtenberger, M. Mühlberger, C. Schelling, W. Schwinger, S. Senz, F. Schäffler, 

Transient-enhanced Si diffusion on natural-oxide-covered Si(0 0 1) nano-structures 

during vacuum annealing, Physica E 23, 442-448 (2004). 

21. J. Stangl, V. Holy, G. Bauer, "Structural properties of self-organized semiconductor 

nanostructures", Rev. Mod. Phys. 76, 725-783 (2004). 

22. M. Peruzzi, J.D. Pedarnig, D. Bäuerle, W. Schwinger, F. Schäffler, "Inclined ZnO thin 

films produced by pulsed-laser deposition", Appl. Phys. A 79, 1873-1877 (2004). 

23. H. Malissa, W. Jantsch, M. Mühlberger, F. Schäffler, Z. Wilamowski, M. Draxler, P. 

Bauer, "Anisotropy of g-factor and electron spin resonance linewidth in modulation 

doped SiGe quantum wells", Appl. Phys. Lett. 85, 1739-1741 (2004). 

24. K. Lai, W. Pan, D.C. Tsui, S. Lyon, M. Mühlberger, F. Schäffler, "Two-flux composite 

fermion series of the fractional quantum hall states in strained Si", Phys. Rev. Lett. 

93, 156805-1/4 (2004). 

25. S. Danis, V. Holy, Z. Zhong, G. Bauer, O. Ambacher, "High-resolution diffuse x-ray 

scattering from threading dislocations in heteroepitaxial layers", Appl Phys Lett. 85, 

3065-3067 (2004). 

26. J. Stangl, T. Schülli, A. Hesse, V. Holy, G. Bauer, M. Stoffel, O.G. Schmidt, "Structural 

properties of semiconductor nanostructures from x-ray scattering", Adv. in Solid 

State Phys. 44, 227-237 (2004). 

27. O. Caha, V. Krapek, V. Holý, S.C. Moses, J.H. Li, A.G. Norman, A. Mascarenhas, 

J.L. Reno, J. Stangl, M. Meduna, "X-ray diffraction on laterally modulated 

(InAs)n/(AIAs)m short-period superlattices", J. Appl. Phys. 96, 4833-4838 (2004). 

28. W. Heiss, R. Kirchschlager, G. Springholz, Z. Chen, M. Debnatz, Y. Oka, "Magnetic 

polaron induced near-band-gap luminescence in epitaxial EuTe", Phys. Rev. B 70, 

035209 035209-1 - 035209-8 (2004).


29. K. Wiesauer, G. Springholz, "Critical thickness and strain relaxation in high-misfit 

heteroepitaxial systems: PbTe1-xSex on PbSe (001)", Phys. Rev. B 69, 245313-1 - 

245313-9 (2004). 

30. O. Kirfel, E. Müller, D. Grützmacher, K. Kern, A. Hesse, J. Stangl, V. Holý, G. Bauer, 

"Shape and composition change of Ge dots due to Si capping", Appl. Surf. Sci. 224, 

139-142 (2004). 

31. J. Fürst, T. Schwarzl, M. Böberl, H. Pascher, G. Springholz, W. Heiss, "Verticalcavity 

surface-emitting lasers in the 8-mm midinfrared spectral range with continuous-wave 

and pulsed emission", IEEE Journal of Quantum Electronics Vol. 40, 966- 

969 (2004). 

32. T. U. Schülli, R. T. Lechner, J. Stangl, G. Springholz, G. Bauer, M. Sztucki, T. H. 

Metzger, "Strain determination in multilayers by complementary anomalous x-ray diffraction", 

Phys. Rev. B 69, 195307-1/8 (2004). 

33. T. U. Schülli, R. T. Lechner, J. Stangl, G. Springholz, G. Bauer, M. Sztucki, T. H. 

Metzger, "Strain determination in multilayers by complementary anomalous x-ray diffraction", 

European Synchrotron Radiation Facility (ESRF) Highlíghts 2004, 80-81 


34. K. Koike, I. Makabe, M. Yano, E. Kaufmann, W. Heiss, G. Springholz and M. Böberl, 

"Molecular Beam Epitaxial Growth and Photoluminescence Characterization of 

PbTe/CdTe Quantum Wells for Mid-Infrared Optical Devices", Journal of the Society 

of Materials Science 53, 1328 – 1333 (2004). 

35. M. Böberl, T. Fromherz, T. Schwarzl, G. Springholz, W. Heiss, "IV-VI resonantcavity 

enhanced photodetectors for the mid-infrared", Semicond. Sci. Technol. 19, 

L115-L117 (2004). 

36. F. Sanchez-Almazan, E. Napolitani, A. Carnera, A.V. Drigo, M. Berti, J. Stangl, Z. 

Zhong, G. Bauer, G. Isella, and H. von Känel, "Ge quantification of high Ge content 

relaxed buffer layers by RBS and SIMS", Nuclear Instr. and Methods in Phys. Res. B 

226, 301-308 (2004). 

37. T. Fromherz, "Fourier Transform Spectroscopy", in "Encyclopedia of Modern Optics", 

edited by Robert D. Guenther, Duncan G. Steel and Leopold Bayvel, Elsevier, 

Oxford, 2004, ISBN 0-12-227600-0, p 90-100 . 

38. G. Bauer and G. Springholz, "Lead Salts" in "Encyclopedia of Modern Optics", edited 

by Robert D. Guenther, Duncan G. Steel and Leopold Bayvel, Elsevier, Oxford, 2004, 

ISBN 0-12-227600-0, p 641.


submitted 2004 / in print 

1. G. Springholz, T. Schwarzl and W. Heiss, ”Mid-infrared Vertical Cavity Surface 

Emitting Lasers based on the Lead Salt Compounds”, in: Mid-infrared Semiconductor 

Optoelectronics, ed. A. Krier (Springer-Verlag London, in print). 

2. A.M. Tyryshkin, S.A. Lyon, W. Jantsch, F. Schäffler, “Spin Manipulation of Free 

Two-Dimensional Electrons in Si/SiGe Quantum Wells”, Phys. Rev. Letters, in print. 

3. V. Holy, T.U. Schülli, R.T. Lechner, G. Springholz, G. Bauer, “Anomalous x-ray diffraction 

from self-assembled PbSe/PbTe quantum dots”, J. Alloys and Compounds, in 

print. 

4. D. Chrastina, G. Isella, M. Bollani, B. Rössner, E. Müller, T. Hackbarth, E. Wintersberger, 

Z. Zhong, J. Stangl, H. von Känel, “Thin relaxed SiGe virtual substrates 

grown by low-energy plasma-enhanced chemical vapor deposition”, J. Cryst. Growth, 

in print. 

5. F. Sánchez-Almazán, E. Napolitani, A. Carnera, A.V. Drigo, M. Berti, J. Stangl, Z. 

Zhong, G. Bauer, G. Isella, H. von Känel, “Ge quantification of high Ge content relaxed 

buffer layers by RBS and SIMS”, Nucl. Instr. Meth. B, in print. 

6. E. Wintersberger, M. Meduna, J. Stangl, G. Bauer, T. Schülli, Y. Chriqui, L. Largeau, 

G. Saint-Girons, I. Sagnes, D. Bensahel, Y. Campidelli, O. Kermarrec, “Investigation 

of buried GaAs/Ge/Si (001) interfaces using anomalous x-ray reflectivity”, MRS Proceedings, 

Boston 2004, to be published. 

7. C. V. Falub, M. Meduna, D. Grützmacher, S. Tsujino, E. Müller, H. Sigg, A. Borak, 

T. Fromherz, G. Bauer, “Structural studies of strain-symmetrised Si/SiGe structures 

grown by molecular beam epitaxy”, J. Crystal Growth, in print. 

8. M. Meduna, J. Novak, C.V. Falub, G. Chen, G. Bauer, S. Tsujino, D. Grützmacher, E. 

Müller, Y. Campidelli, O. Kermarrec, D. Bensahel, N. Schell, “High temperature investigations 

of Si/SiGe based cascade structures using x-ray scattering methods”, J. 

Phys. D: Appl. Phys., to be published. 

9. C.P.T. Svensson, W. Seifert, M.W. Larsson, J. Stangl, G. Bauer, L. Samuelson, “Epitaxially 

grown GaP/GaAs1-xPx/GaP double heterostructure nanowires for optical applications”, 

Nanotechnology, in print. 

10. J. Fürst, H. Pascher, T. Schwarzl, G. Springholz, M. Böberl, G. Bauer, W. Heiss, 

“Magnetic field tunable circularly polarized emission form midinfrared IV-VI vertical 

emitting layers”, Appl. Phys. Lett., in print. 

11. G. Springholz, “Three-dimensional stacking of self-assembled quantum dots in multilayer 

structures”, C. R. Physique, in print. 

12. J. Novák, V. Holý, J. Stangl, G. Bauer, E. Wintersberger, S. Kiravittaya, O.G. 

Schmidt, “A method for the characterisation of strain fields in buried quantum dots 

using x-ray standing waves”, J. Phys. D: Appl. Phys., in print.


13. H. Sigg, C.V. Falub, E. Müller, A. Borak, D. Grützmacher, T. Fromherz, M. Meduna, 

O. Kermarrec, “Bandstructure analysis of strain compensated Si/SiGe quantum cascade 

structures”, Elsevier B.V., in print. 

14. D. Grützmacher, S. Tsujino, C. Falub, A. Borak, L. Diehl, E. Müller, H. Sigg, U. Genser, 

T. Fromherz, M. Meduna, G. Bauer, J. Faist, O. Kermarrec, “Transport and absorption 

in strain-compensated Si/Si1-xGex multiple quantum well and cascade structures 

deposited on Si0.5Ge0.5 pseudosubstrates”, Materials Science in Semiconductor 

Processing, in print. 

15. T.U. Schülli, M. Stoffel, A. Hesse, J. Stangl, R.T. Lechner, E. Wintersberger, M. 

Sztucki, T.H. Metzger, O.G. Schmidt, G. Bauer, “Influence of growth temperature on 

interdiffusion in uncapped SiGe-islands on Si(001) determined by anomalous x-ray 

diffraction and reciprocal space mapping”, Phys. Rev., in print. 

16. R. T. Lechner, G. Springholz, T. U. Schülli, J. Stangl, T. Schwarzl, G. Bauer, “Strain 

induced changes in the magnetic phase diagram of metamagnetic heteroepitaxial 

Eu/Se/PbSe1-xTex multilayers”, Phys. Rev. Lett., in print. 

17. T. Fromherz, M. Meduna, G. Bauer, A. Borak, C.V. Falub, S. Tsuijino, H. Sigg, D. 

Grützmacher, “Intersubband absorption of strain compensated Si1-xGex valenceband 

quantum wells with 0.7


25. T. M. Burbaev, V. A. Kurbatov, M. M. Rzaev, A. O. Pogosov, N. N. Sibel'din, V. A. 

Tsvetkov, H. Lichtenberger, F. Schäffler, J. P. Leitao, N. A. Sobolev, and M. C. 

Carmo, “Morphological transformation of a Germanium layer grown on a Silicon 

surface by Molecular-Beam Epitaxy at low temperatures”, Phys. Solid State, submitted. 

26. J.P. Leitão, A. Fonseca, N.A. Sobolev, M.C. Carmo, N. Franco, A.D. Sequeira, T.M. 

Burbaev,V.A. Kurbatov, M.M. Rzaev, A.O. Pogosov, N.N. Sibeldin, V.A. Tsvetkov, 

H. Lichtenberger, and F. Schäffler, “Low-temperature molecular beam epitaxy of Ge 

on Si”, Materials Science in Semiconductor Processing, in print. 

27. M. Rzaev, F. Schäffler, V. Vdovin and T. Yugova, “Misfit dislocation nucleation and 

multiplication in fully strained SiGe/Si heterostructures under thermal annealing”, 

Materials Science in Semiconductor Processing, in print. 

28. M. Draxler, M. Mühlberger, F. Schäffler and P. Bauer, “Non-destructive quantitative 

analysis of the Ge concentration in SiGe quantum wells by means of low energy RBS”, 

Nucl. Inst. Meth., in print 2005. 

29. J. Stangl, T. Schülli, A. Hesse, G. Bauer, V. Holy, “X-ray scattering methods for the 

study of epitaxial self-assembled quantum dots”, In: Quantum Dots: Fundamentals, 

Applications, and Frontiers, eds.: B.A. Joyce et al., Springer, Netherlands, in print. 

30. H. Lichtenberger, M. Mühlberger and F. Schäffler, "Ordering of Si0.55Ge0.45 Islands on 

Vicinal Si(001) Substrates: The Interplay between Kinetic Step Bunching and Strain- 

Driven Island Growth", Appl. Phys. Lett., in print. 

31. G. Chen, H. Lichtenberger, F. Schäffler, G. Bauer, W. Jantsch, "Geometry dependence 

of nucleation mechanism for SiGe islands grown on pitpatterned Si(001) substrates", 

Mat. Science Engineering C, ELSEVIER, in print. 

News Coverage 

1. "Linz wird österreichisches Zentrum für die Nanotechnologie-Forschung"Vernetzung 

im Reich der Zwerge, Kronenzeitung issued 08.10.2004; News Coverage of the NSI 

Project Cluster funded by the Austrian Nano Initiative 

2. "In kleinen Dimensionsen denken", Der Standard Forschung Spezial, issued 

02.11.2004; Interview with F. Schäffler, coordinator of the NSI Project Cluster funded 

by the Austrian Nano Initiative 

3. "Vernetzung im Reich der Zwerge" von F. Schäffler in "News vom Campus" of Johannes 

Kepler University, Issue 23, Mai 2004.

Part A: Semiconductor Physics Group Talks and Presentations 47 

Invited Talks 

Talks and Presentations 

1. F. Schäffler, "Nanostructured Semiconductors: Top-Down and Bottom-Up Techniques", 

IIR Nano-Seminar, Vienna, 29.09.2004 

2. F. Schäffler, "Growth Instabilities on Si(001):from Kinetic Step Bunching to Perfectly 

Ordered SiGe Islands", MRS Fall Meeting, Boston, USA, 29.11. - 03.12.2004 

3. J. Stangl, Structural Properties of Semiconductor Nanostructures from X-Ray Scattering 

DPG-Frühjahrstagung Regensburg, March 8, 2004. 

4. J. Stangl, Influence of growth parameters on the composition of SiGe islands: an x-ray 

diffraction study”, Summerschool "Jaszowiec 2004", Jaszowiec, Poland, June 3, 2004. 

5. J. Stangl, “High resolution x-ray diffractometry: Determination of strain and composition”, 

XTOP Prague, Czech Republic, Sept. 8, 2004. 

6. G. Bauer, “Growth and characterization of semiconductor nanostructures”, 20th General 

Conference of the Condensed Matter Division of the European Physical Society (EPS), 

Prague, July 19-20, 2004. 

7. G. Bauer, Z. Zhong, G. Springholz, R. T. Lechner, J. Stangl, T. Schüllli, T. H. Metzger, 

V. Holy, “Nanostructure growth and self-assembly”, ESRF Workshop on Surfaces and 

Interfaces, Grenoble, Sept. 29 - Oct. 02, 2004. 

8. G. Bauer, “Nanostructure growth and self-assembly”, ALBA Workshop Universidad 

Autonoma de Madrid, Nov. 3-4, 2004. 

Kolloquia and Seminar Talks 

1. G. Bauer, „Strukturelle Untersuchungen an Halbleiter-Nanostrukturen“, Kolloquiumsvortrag 

Universität Jena, July 5, 2004. 

2. F. Fromherz, P. Rauter, G. Bauer, “SiSiGe cascade structures: structural characterization 

and optical properties”, Kolloquiumsvortrag Universität Prag, May 20-21, 2004. 

3. J. Stangl, “Investigation of semiconductor nanostructures by x-ray diffraction techniques”, 

Symposium on the Use of Synchrotron Radiation, Vienna, 15 March 2004. 

4. Z. Zhong, “Site-controlled Ge islands grown on the patterned Si substrates”, Seminar 

Talk, Max Planck Institut für Festkörperforschung Stuttgart (Abt. Von Klitzing), Dec. 13, 

2004. 

5. F.Schäffler, "Si-based Heterostructures"; SiGe-Net project meeting, Linz 02.02.2004 

6. F. Schäffler, "Presentation of the NanoScience/Technology Center Linz", Annual Meeting 

of the Austrian Physical Society, Linz, 28. - 30.10.2004 

7. G. Springholz, ”Strain relaxation and dislocation formation in strained-layer heteroepitaxy”, 

Forschungszentrum Jülich, Germany, 4.11.2004. 

8. G. Springholz, ”Surface and Interface Structure in Heteroepitaxial Systems”, Montanuniversität 

Leoben, Austria 26.2.2004.

48 Talks and Presentations Part A: Semiconductor Physics Group 

Conference Presentations (Talks and Posters) 

1. H. Lichtenberger, M. Mühlberger, C. Schelling and F. Schäffler, Ordering of Self- 

Assembled Si0.55Ge0.45 Islands on Vicinal Si(001) Substrates, 13th Int. Conf. on Molecular 

Beam Epitaxy, Edinburgh, UK, 23. - 27.08.2004 

2. G. Pillwein und G. Brunthaler, "Leitwertfluktuationen im Coulomb Blockade Regime von 

AlGaAs Quantenpunkten", Annual Meeting of the Austrian Physical Society, Linz, 28. - 

30.10.2004. 

3. H. Lichtenberger, M. Mühlberger, C. Schelling, F. Schäffler, "Ordering of Self- 

Assembled Si0.55Ge0.45 Islands on Vicinal Si(001) Substrates", Annual Meeting of the Austrian 

Physical Society, Linz, 28. - 30.10.2004 

4. G. Pillwein, G. Brunthaler, G. Strasser, “Fabrication and Characterization of lateral quantum 

dots in GaAs/AlGaAs Heterostructures”, Poster, 13th Int. Winterschool on New Developments 

in Solid State Physics, 15. - 20. Feb. 2004, Mauterndorf, Salzburg. 

5. M. Böberl, W. Heiss, T. Schwarzl, and G. Springholz, Z. Wang, K. Reimann, and M. 

Woerner (Poster),”Dynamics of lead-salt microcavity lasers after femtosecond optical excitation”, 

13 th International Winterschool on New Developments in Solid State Physics: 

“Low-Dimensional Systems”, Mauterndorf, Austria, February 15 – February 20, 2004. 

6. E. Kaufmann, W. Heiss, G. Springholz, M. Böberl, T. Schwarzl, M. Yano, I. Makabe, K. 

Koike, (Poster), “Continuous-wave midinfrared photoluminescence of IV-VI and IV-VI/II- 

VI heterostructures”, 13 th International Winterschool on New Developments in Solid 

State Physics: “Low-Dimensional Systems”, Mauterndorf, Austria, February 15 – February 

20, 2004 

7. R. T. Lechner, T. U. Schuelli, V. Holy, G. Springholz, J. Stangl, A. Raab, T. H. Metzger, 

G. Bauer (Talk), “Fabrication and characterization of three dimensional ordered quantum 

dot lattices using self assembled epitaxy“, Spring Meeting of the Materials Research 

Society, San Francisco, USA, 12.4.-16.4.2004. 

8. R. T. Lechner, T. U. Schuelli, S. Dhesi, P. Bencok, J. Stangl, G. Springholz and G. Bauer 

(Talk), „Laterally ordered magnetic EuSe quantum dots“, Spring Meeting of the Materials 

Research Society, San Francisco, USA, 12.4.-16.4.2004. 

9. M. Böberl, T. Schwarzl, G. Springholz und W. Heiss, J. Fürst, H. Pascher (Talk), Bleisalzverbindungen 

für optische Bauelemente im mittleren Infraroten, Infrarot-Kolloquium, 

Feiburg, Germany, 20-21.4.2004. 

10. K. Rumpf, P. Granitzer, S. Janecek, G. Springholz , H. Krenn, “Ideal and real behaviour 

of the magnetic phase transitions of low-dimensional antiferromagnetic EuTe/PbTesuperlattices“, 

Joint European Magnetic Symposia JEMS’04, Dresden, Germany, 05-10, 

2004. 

11. K. Rumpf, P. Granitzer, S. Janecek, G. Springholz , H. Krenn, “Magnetic Phase Diagram 

of low-dimensional EuTe/PbTe-Multi-quantum Wells Measured by SQUIDmagnetometry“, 

8 th Int. Conf. on Nanometer-Scale Science and Technology, Venice, Italy, 

28.6.-2.7.2004. 

12. T. Schwarzl, J. Fürst, M. Böberl, H. Pascher, G. Springholz, W. Heiss (Talk), “Continuous-wave 

emission from vertical-cavity surface-emitting lasers at long wavelengths of 8 

microns“, 6 th International Conference on Mid-Infrared Optoelectronic Materials and Devices, 

28.6-1.7.2004, St. Petersburg, Russia.



Koike (Poster), “Continuous-wave light emission from PbTe based heterostructures with 

CdTe or PbEuTe barriers“, 6 th International Conference on Mid-Infrared Optoelectronic 

Materials and Devices, 28.6-1.7.2004, St. Petersburg, Russia. 

14. E. Baumgartner, T. Schwarzl, G. Springholz, W. Heiss (Poster), “Omnidirectional laserquality 

Bragg mirrors with broad stop bands in the mid-infrared“, 6 th International Conference 

on Mid-Infrared Optoelectronic Materials and Devices, 28.6-1.7.2004, St. Petersburg, 

Russia. 

15. M. Simma, T. Fromherz, G. Springholz and G. Bauer (Poster), “Mid-infrared photocurrent 

spectroscopy on self-organized PbSe quantum dots“, 6 th International Conference on 

Mid-Infrared Optoelectronic Materials and Devices, 28.6-1.7.2004, St. Petersburg, Russia. 

16. G. Springholz, D. Lugovy, R. T. Lechner, A. Raab, L. Abtin, V. Holy, G. Bauer (Talk), 

“Size effects and shape transitions in self-organized ordering of PbSe/PbEuTe quantum 

dot superlattices“, 14 th International Conference on Crystal Growth and 12 th International 

Conference on Vapor Growth and Epitaxy, 9.-13.8.2004, Grenoble, France. 

17. R Kirchschlager, W. Heiss, R. T. Lechner, G. Bauer, G. Springholz, ”Hysteresis loops of 

the energy band gap and effective g-factor up to 18000 for metamagnetic EuSe epilayers”, 

27 th International Conference on the Physics of Semiconductors, 26.7.-31.7.2004, 

Flagstaff, USA. 

18. G. Springholz, T. Schwarzl, E. Baumgartner, W. Heiss (Talk), “Molecular beam epitaxy 

of wide/narrow band gap semiconductors for mid-infrared broad-band Bragg mirrors and 

high finesse microcavities“, 13 th International Conference on Molecular Beam Epitaxy, 

22.-27.8.2004, Edinburgh, UK. 

19. R. T. Lechner, G. Springholz, T. U. Schülli, L. Abtin, H. Krenn, and G. Bauer (Talk), “In 

and ex situ characterisation of magnetic EuSe/PbSe1-xTex superlattices grown by molecular 

beam epitaxy“, 13 th International Conference on Molecular Beam Epitaxy, 22.- 

27.8.2004, Edinburgh, UK. 

20. D. Lugovyy, G. Springholz, P. Simiceck and V. Holy (Poster), “Monte Carlo simulation 

and growth of vertical and lateral ordering in self-assembled PbSe quantum dot superlattices“, 

13 th International Conference on Molecular Beam Epitaxy, 22.-27.8.2004, Edinburgh, 

UK. 

21. T. Schwarzl, J. Fürst, M. Böberl, H. Pascher, G. Springholz, W. Heiss (Talk), “MBE 

growth of vertical-emitting microcavity lasers for the 6 - 8 micron spectral range operating 

in continuous-wave mode“, 13 th International Conference on Molecular Beam Epitaxy, 


22. L. Abtin, A. Raab, G. Springholz and V. Holy (Talk), “Surface evolution and shape 

transitions of self-assembled PbSe quantum dots during overgrowth“, 13 th International 

Conference on Molecular Beam Epitaxy, 22.-27.8.2004, Edinburgh, UK. 

23. G. Springholz and K. Wiesauer (Talk), “Quasi-Periodic Nanopatterning of Strain- 

Relaxed Heteroepitaxial Layers by Misfit Dislocation Arrays as Demonstrated for PbTe 

on PbSe (001)”, Fall Meeting of the Materials Research Society, 29.11.-3.12.2004, Boston, 

USA.

50 Talks and Presentations Part A: Semiconductor Physics Group 

24. G. Springholz, T. Schwarzl, J. Fürst, M. Böberl, H. Pascher, W. Heiss (Talk), “Vertical- 

Cavity Surface-Emitting Lasers with cw-Emission at Long Wavelengths of 6-8 Microns”, 

Fall Meeting of the Materials Research Society, 29.11.-3.12.2004, Boston, USA. 


Koike, “Continuous-wave light emission from PbTe based heterostructures with CdTe or 

PbEuTe barriers“, 6 th International Conference on Mid-Infrared Optoelectronic Materials 

and Devices, 28.6-1.7.2004, St. Petersburg, Russia. 

26. E. Baumgartner, T. Schwarzl, G. Springholz, W. Heiss, “Omnidirectional laser-quality 

Bragg mirrors with broad stop bands in the mid-infrared“, 6 th International Conference 

on Mid-Infrared Optoelectronic Materials and Devices, 28.6-1.7.2004, St. Petersburg, 

Russia. 

27. M. Simma, T. Fromherz, G. Springholz and G. Bauer, “Mid-infrared photocurrent spectroscopy 

on self-organized PbSe quantum dots“, 6 th International Conference on Mid- 

Infrared Optoelectronic Materials and Devices, 28.6-1.7.2004, St. Petersburg, Russia. 

28. G. Springholz, D. Lugovy, R. T. Lechner, A. Raab, L. Abtin, V. Holy, G. Bauer, “Size 

effects and shape transitions in self-organized ordering of PbSe/PbEuTe quantum dot superlattices“, 

14 th International Conference on Crystal Growth and 12 th International Conference 

on Vapor Growth and Epitaxy, 9.-13.8.2004, Grenoble, France. 

29. R Kirchschlager, W. Heiss, R. T. Lechner, G. Bauer, G. Springholz, ”Hysteresis loops of 

the energy band gap and effective g-factor up to 18000 for metamagnetic EuSe epilayers”, 

27 th International Conference on the Physics of Semiconductors, 26.7.-31.7.2004, 

Flagstaff, USA. 

30. G. Springholz, T. Schwarzl, E. Baumgartner, W. Heiss, “Molecular beam epitaxy of 

wide/narrow band gap semiconductors for mid-infrared broad-band Bragg mirrors and 

high finesse microcavities“, 13 th International Conference on Molecular Beam Epitaxy, 


31. R. T. Lechner, G. Springholz, T. U. Schülli, L. Abtin, H. Krenn, and G. Bauer, “In and ex 

situ characterisation of magnetic EuSe/PbSe1-xTex superlattices grown by molecular beam 

epitaxy“, 13 th International Conference on Molecular Beam Epitaxy, 22.-27.8.2004, Edinburgh, 

UK. 

32. D. Lugovyy, G. Springholz, P. Simiceck and V. Holy, “Monte Carlo simulation and 

growth of vertical and lateral ordering in self-assembled PbSe quantum dot superlattices“, 

13 th International Conference on Molecular Beam Epitaxy, 22.-27.8.2004, Edinburgh, 

UK. 

33. T. Schwarzl, J. Fürst, M. Böberl, H. Pascher, G. Springholz, W. Heiss, “MBE growth of 

vertical-emitting microcavity lasers for the 6 - 8 micron spectral range operating in continuous-wave 

mode“, 13 th International Conference on Molecular Beam Epitaxy, 22.- 

27.8.2004, Edinburgh, UK. 

34. L. Abtin, A. Raab, G. Springholz and V. Holy, “Surface evolution and shape transitions 

of self-assembled PbSe quantum dots during overgrowth“, 13 th International Conference 

on Molecular Beam Epitaxy, 22.-27.8.2004, Edinburgh, UK. 

35. G. Springholz and K. Wiesauer, “Quasi-Periodic Nanopatterning of Strain-Relaxed Heteroepitaxial 

Layers by Misfit Dislocation Arrays as Demonstrated for PbTe on PbSe 

(001)”, Fall Meeting of the Materials Research Society, 29.11.-3.12.2004, Boston, USA.


36. G. Springholz, T. Schwarzl, J. Fürst, M. Böberl, H. Pascher, W. Heiss, “Vertical-Cavity 

Surface-Emitting Lasers with cw-Emission at Long Wavelengths of 6-8 Microns”, Fall 

Meeting of the Materials Research Society, 29.11.-3.12.2004, Boston, USA. 

37. 42. S. Tsujino, A. Borak, C. V. Falub, E. Müller, L. Diehl, M. Scheinert, H. Sigg, D. 

Grützmacher, T Fromherz, U. Gennser, Y. Campidelli, O. Kermarrec, D. Bensahel, J. 

Faist, "Quantum transport of s quasi-two-dimensional hole gas in strain compensated 

SiGe wells and superlattices", 13th International Winterschool on New Developments in 

Solid State Physics, Low-Dimensional Systems, Mauterndorf, Austria, 15-20 Feb. 2004. 

38. D. Grützmacher, C. Falub, S. Tsujino, A. Borak, M. Scheinert, E. Müller, H. Sigg, M. 

Meduna, T. Fromherz, G. Bauer, "Achievements and challenges on the road to a SiGe 

quantum cascade laser", 12th International Symposium Nanostructures: Physics and 

Technology St Petersburg, Russia, 21–25 June 2004 

39. M. Simma, T. Fromherz, A. Raab, G. Springholz, G. Bauer, „Mid-Infrared photocurrent 

spectroscopy on self-organized PbSe quantum dots“, 6th International Conference on Mid 

Infrared Optoelectronics Materials and Devices (MIOMD-VI), 28 June-1 July 2004, St. 

Petersburg, Russia. 

40. T. Fromherz, M. Meduna, G. Bauer, A. Borak, C. V. Falub, S. Tsujino, H. Sigg, D. 

Grützmacher, "Bandstructure and in-plane transport in Ge rich, strain symmetrized, high 

quality SiGe quantum wells on Si0.5Ge0.5 pseudosubstrates", 27th International Conference 

on the Physics of Semiconductors (ICPS 27), Flagstaff, Arizona July 26- 30, 2004. 

41. T. Fromherz, M. Grydlik, P. Rauter, M. Meduna, C. Falub, L. Diehl, G Dehlinger, H. 

Sigg,, D. Grützmacher, H. Schneider, G. Bauer, "Si/SiGe QWIPs for voltage-tuneable, 

resonator-enhanced, two-colour detection in the MIR", 3rd International Workshop on 

Quantum Well Infrared Photodetectors (QWIP 2004), Kananaskis, Alberta, Canada, August 

7-13, 2004. 

42. C.V. Falub, M. Meduna, E. Müller, S. Tsujino, A. Borak, T, Fromherz, H. Sigg, O. Kermarrec, 

G. Bauer, D. Grützmacher, "Structural studies of complex strain symmetrized 

SiGe structures grown by molecular beam epitaxy", International Conference on Molecular 

Beam Epitaxy (MBE2004), Edinburgh, UK, August 22 – 27

52 Funded Projects Part A: Semiconductor Physics Group 

Funded Research Projects 

Projects funded by „Fonds zur Förderung der Wissenschaftlichen 

Forschung (FWF)” (Austrian Science Foundation) 

1. P14684-N08 

“Kontrollierte Positionierung selbstorganisierter SiGe-Inseln” 

1. Mar. 2001 - 28. Feb. 2005 

Project leader: G. Bauer 

2. P16160-N08 

“Metallischer Zustand in zweidimensionalen Halbleiterstrukturen” 

1. Jan. 2003 – 31. Dec. 2005 

Project leader: G. Brunthaler 

3. P16223-N08 

“Kinetische und spannungsinduzierte Selbstorganisation auf Si” 

1. Feb. 2003 - 31. Jan. 2006 

Project leader: F.Schäffler 

4. P17166-N08 

"Selbst-organisierte IV-VI Halbleiterquantenpunkte" 

1. April 2004 – 31. March 2007 

Project Leader: G. Springholz 

5. P15583-N08 

"Bleisalz Mikroresonatorlaser für das mittlere Infrarot", 

1. Jan. 2003 - 31. May 2005 

Project leader: G. Springholz 

6. P17436-N08 

”STM Untersuchung von ortskontrollierten SiGe Nanoinseln” 

1. Dec. 2004 – 30. Nov. 2007 

Project leader: G. Springholz 

7. F 2512-N08 

“IR Emission and Detection by Group IV Nanostructures” 

(part of SFB025 Infrared Optical Nanostructures: IRON) 

01. March 2005 – 29. Febr. 2009 

Project leader: T. Fromherz 

8. F 2502-N08 

“SiGe Nanostructures” 

(part of the SFB Infrared Optical Nanostructures IRON) 

01. March 2005 – 29. Febr. 2009 

Project leader: F. Schäffler 

9. F 2504-N08 

“Epitaxial Lead Salt Nanostructures” 


01. March 2005 – 29. Febr. 2009 

Project leader: G. Springholz

Part A: Semiconductor Physics Group Funded Projects 53 

10. F 2507-N08 

“Next Generation X-ray Techniques” 


01. March 2005 – 29. Febr. 2009 

Project leader: J. Stangl, G. Bauer 

Projects funded by the European Community 

1. EC contract No. HPRN-CT-1999-00123 

“SiGeC Nanostructures: a new path to Silicon based optoelectronics (SiGeNET)”, 

Participants: G. Bauer (Univ. Linz, A, Project Coordinator), J. Derrien and I. Berbezier 

(Centre National de la Recherche Scientifique CNRS, Marseille, F), M. Berti (Istituto Nazionale 

per la Fisica della Materia INFM, Padova, I), P. Kelires (Foundation for Research 

and Technology Hellas FORTH, Heraklion, GR), K. Eberl (MPI für Festkörperforschung, 

Stuttgart, D), D. Grützmacher and M. Eberle (Paul Scherrer Institut, PSI, Villigen, CH). 

01 Mar. 2000 - 29 Feb. 2004 

2. INTAS project No. 2001-2212 

”Electron quantum liquids and quantum solids of reduced dimensionality in molecular 

organic and inorganic host lattices” 

Participants: G. Bauer (Semiconductor Physics, Univ. Linz, Austria), J. Singleton (Oxford 

University, Oxford, UK), S. Brazovski (CNRS/University Paris-Sud, Orsay, France), 

N.D. Kushch (Institute of Problems of Chemical Physics, Chernogolovka, Russia), V. Pudalov 

(Lebedev Institute, Moscow, Russia), S. Dorozhkin (Institute of Solid State Physics/RAS, 

Chernogolovka, RU), A.G. Lebed (Landau Institute of Theoretical Physics, 

Moscow, Russia), E.G. Batyev (Institute of Semiconductor Physics of the Siberian 

Branch of RAS, Novosibirsk, Russia) 

01 June 2002 - 31 May 2004 

3. INTAS project No. 03-51-5015 

“Self-organized ultra small Ge quantum dots in Si with very high density for nanoelectronics” 

Participants: E. Kasper (Institute of Semiconductor Engineering Stuttgart, Germany), N. 

Sobolev (University of Aveiro, Department of Physics, Aveiro, Portugal), F. Schäffler 

(Semiconductor Physics, Univ. Linz, Austria), A. I. Nikiforov (Institute of Semiconductor 

Physics, Department of Growth and Structure of Semiconductor Materials, Novosibirsk, 

Russia), K. Bakhronovich Ashurov (Institute of Electronics, Department of adsorptional 

and emissional effects, Tashkent, Uzbekistan), V. A. Kurbatov (P.N. Lebedev Physical 

Institute, Moscow, Russia), Y. Yurievich Hervieu (Tomsk State University, Tomsk, Russia). 

01 April 2004 – 31 March 2007 

4. EC contract No. G5RD-CT-2001-00558 

“Economical Production of SiGe material for Microelectronics and optoelectronics applications 

(ECOPRO)”, 

Participants: G. Bomchil (ST Microelectronics, Crolles, France), J. Ramm (Unaxis 

Balzers Ltd, Liechtenstein), G. Redmond (National Microelectronics Research Centre, 

Cork, Ireland), I. Sagnes (Centre National de la Recherche Scientifique, Bagneux, 

France), H. von Kaenel (Politecnico de Milano, Italy), E. Parker (University of Warwick,

54 Funded Projects Part A: Semiconductor Physics Group 

Coventry, UK), G. Bauer, J. Stangl (University of Linz, Austria). 

01 Sept. 2001 – 31 Aug. 2004 

5. EC Contract No. IST-2001-38035 

“Silicon Heterostructure Intersubband Emitters (SHINE)” 

Participants: D. Paul (University of Cambrige, Cavendish Laboratory, Cambridge, UK), 

Wei-Xin Ni (Linkoepings University, Linköping, Sweden), P. Lugli (Universita’ Degli 

Studi di Roma “Tor Vergata”, Genova, Italy), W. Tribe (Teraview Limited, Cambridge, 

UK), C. Sirtori (Thales, Orsay, France), C. Pidgeon (Heriot-Watt-University, Edinburgh, 

UK), J. Faist (Université de Neuchatel, Neuchatel, Switzerland), G. Bauer, T. Fromherz 

(University of Linz, Austria), D. Grützmacher (Paul Scherrer Institut, Villigen, Switzerland) 

01 Jan. 2003 - 31 Dec. 2005. 

6. EC contract No. NMP4-CT-2004-500101 

”Self-Assembled Semiconductor Nanostructures for New Devices in Photonics and Electronics 

(SANDIE) ” 

Participants: Katholieke Universiteit Leuven, B; Universiteit Antwerpen, B; Technische 

Universität Berlin, D; Lunds Universitet, Lund, S; Technische Universiteit Eindhoven, 

NL; University of Sheffield, UK; University of Nottingham, UK; Heriot-Watt University, 

Edinburgh, UK; Centre National de la Recherche Scientifique, Paris, F; Institut-Nationaldes-Sciences-Appliquées 

de Rennes, F; Université Paris-Sud XI, F; Consiglio Nazionale 

delle Ricerche – Instituto dei Materiali per lÈlettronica e il Magnetismo, Parma, I; Universidade 

de Aveiro, Portugal; Universitat de Valencia Estudi General, Valencia, Spain; 

Universidad de Cadiz, Spain; Bookham Technology PLC, Abingdon, UK; Universität 

Dortmund, D; AIXTRON AG, Aachen, D; Consejo Superior de Investigaciones Científicas, 

Madrid, Spain; Technische Universität Wien, A; Toshiba Research Europe Ltd, 

Cambridge, UK; A.F. Ioffe Physico-Technical Institute, St. Petersburg, RU; Fritz-Haber- 

Institut der Max-Planck-Gesellschaft, Berlin, D; NSC Nanosemiconductors GmbH, 

Dortmund, Germany; Johannes Kepler University, Linz, A; 

01 July 2004 – 30 June 2008. 

Projects funded by „Gesellschaft für Mikroelektronik” 

1. “Clean Room Linz” 

01 Jan. 2004 – 31 Jan. 2004 

(a part of this amount supporting the group of Prof. W. Jantsch) 

Project Leader: G. Brunthaler

Part A: Semiconductor Physics Group: Extramural Activities 55 

Extramural Activities 

Gesellschaft für Mikroelektronik (GMe) 

Günther Bauer is vice president of the GMe for the period Jan 2005 to Dec 2006. 

The GMe Vienna supports University-based high technology research in the areas of semiconductor 

technology, microelectronics, optoelectronics, and sensors in Austria. In 2003 the 

funding provided by the Ministerium für Verkehr, Innovation und Technologie for the GMe 

to the institutions at the Technical University of Vienna and at the Johannes Kepler University 

Linz was crucial for maintaining the research infrastructure at the clean rooms. This seed 

money helped to acquire additional funds through a number of projects, which in their total 

amount exceeded the seed money spent by the GMe by about a factor of eight. Quite a number 

of contributions in this annual report would not have been possible without the support 

from GMe. 

The activities of the GMe are documented in the annual report available under the web address 

http://gme.tuwien.ac.at. 

Fonds zur Förderung der wissenschaftlichen Forschung 

(FWF) (Austrian Science Fund) 

Günther Bauer is member of the board of the Austrian Science Fund. 

The Austrian Science Fund is the main institution in Austria which supports basic research in 

all scientific disciplines. The FWF supports not only projects of individual researchers but 

also project clusters like special research programmes, national research networks, and provides 

special funding for groups of PhD students in “Doktoratskollegs”. It also has several 

programmes for stipends for individuals who intend to spend post-doc years (Schrödinger 

stipends) abroad and for those wishing to return to Austria, and furthermore for supporting 

women in science (Firnberg stipends, Elise Richter programme). The decision on funding all 

these projects is entirely based on their evaluation by international peers. In 2004 the total 

amount dedicated to the various programmes was slightly above 100 Mio €. In addition, the 

FWF administers the Wittgenstein and START programme of the Austrian Ministry for Education 

Science and Culture. With this programme eminent scientists by international standards 

may receive the Wittgenstein prize. START prizes are awarded to excellent younger scientists 

(aged below 35). The decisions on these awards are made by an International Jury. 

More information on the FWF can be found at: http://www.fwf.ac.at.

56 Industrial Collaborations Part A: Semiconductor Physics Group 

Industrial Collaborations 

1. AMS, Unterpremstätten, Austria: Research Collaboration (F. Schäffler). 

2. E+E Elektronik, Engerwitzdorf, Austria: Subcontract within FFF project 805903 

(F.Schäffler). 

3. Profactor Produktionsforschungs GmbH, Steyr-Gleink, Austria. 

4. ST Microelectronics, Crolles, France, and UNAXIS, Trübach, Switzerland (within the 

framework of ECOPro) 

5. Teraview Limited, Cambridge, UK, and Thales, Orsay, France (within the framework of 

SHINE) 

Conference Organizations 

13 th Int. Winterschool on New Developments in Solid State Physics on "Low-Dimensional 

Systems", organized by G. Bauer, W. Jantsch, F. Kuchar, 15.-20. Feb. 2004, Mauterndorf, 

Province of Salzburg, Austria. 

Education and Training of 

High School Teachers 

G. Brunthaler, “Creation of new examples for local competitions of the Physics Olympiade in 

Austria”, April 2004. 

Awards 

J. Stangl received on Nov. 12 th 2004 the "Talentförderungspreis" of the Land Upper Austria 

for his work on "Determination of strain and chemical composition of self organized semiconductor 

islands".

Part B 

Abteilung Festkörperphysik 

– 

Solid State Physics Group

58 Personnel Part B: Solid State Physics Group

Part B: Solid State Physics Group Personnel 59 

Personnel 

The scientific-personnel structure of the solid state physics group consist of: 

o 2 permanent professor positions (granted by ministry of science) 

o 3 permanent scientific member positions (granated by ministry of science) 

o 2 non-permanent scientific member positions (granted by ministry of science) 

o 10 non-permanent scientific member positions (granted by FWF, ÖNB, BMfFWK), 

Thus, for each scientific staff member granted by ministry of science on average 1 non- 

permanent research position was acquired through granted research projects. 

Scientific staff 

Researchers funded by ministry of science 


Helmut Heinrich 1 Dr. O.Univ.-Prof. 

Wolfgang Jantsch Dr. Univ.-Prof. 

Wolfgang Heiß Doz. Dr. Ao.-Prof. 

Leopold Palmetshofer Doz. Dr. Ao.-Prof. 

Helmut Sitter Doz. Dr. Ao.-Prof. 

Alberta Bonanni Dr. Univ.-Ass. 

Andrej Andreev Dr. Univ.-Ass. 



Joachim Achleitner DI 

Eugen Baumgartner DI FWF 

Michaela Böberl DI FWF 

Erich Kaufmann DI FWF 

Maksym Kovalenko 2 M. Sc. FWF 

Hans Malissa DI WiMi 

Jürgen Roither DI FWF 

Klaus Schmidegg DI EU-Projekt ISCE-MOCVD 3 / FWF 4 

Clemens Simbrunner 5 DI EU-Projekt ISCE-MOCVD 

1 emeritus since 30.09.04 

2 since 01.10.04 

3 until 31.08.04 

4 since 01.09.04

60 Personnel Part B: Solid State Physics Group 

Walter Söllinger DI FWF 

Post docs 


Gang Chen 6 Dr. FWF 

Alberto Montaigne-Ramil Dr. FWF 

Thomas Schwarzl Dr. FWF 


name 

Johannes Anzengruber 

Raimund Kirchschlager 

Stefan Pichler 

Matthias Wegscheider 

graduated 

Technical and support staff 

name position 

Svetlana Andreeva laboratory technician 

Johanna Firmberger apprentice 

Otmar Fuchs technician 

Klaus Haselgrübler 7 laboratory technician 

Elisabeth Wirtl 8 physics laboratory assistant 

Josef Jägermüller mechanic 

Evelyn Rund administration 

Ekkehard Nusko electronics engineer 

5 since 01.03.04 

6 since 01.01.04 

7 until 31.03.04 

8 since 04.05.04

Part B: Solid State Physics Group Personnel 61 

Visiting researchers 


Eduard Belas Karls-Universität Prag 4 days 

Marina Bodnartschuk Institute of Physical Chemistry 

National Institute of Scince of Ukraine 

29 days 

Ian Franc Karls Universität Prag 4 days 

Daniel Franta Masyryk University Brno 20 days 

Sergey Ganichev Universität Regensburg 3 days 

Vasyl Glukhanyuk IFPAN, Warsaw 21 days 

Ivan Hotovy TU Bratislava 18 days 

Yuri Khalavka University Chernivtsi, Ukraine 14 days 

Maksym Kovalenko Institute of Inorganic Chemistry 

University of Chernivtsi, Ukraine 

57 days 

Adrian Kozanecki IFPAN, Warsaw 19 days 

Jozef Liday TU Bratislava 18 days 

Ben Murlin University of Surrey, Guildford, UK 5 days 

Ivan Ohlidal Mayryk University Brno 20 days 

Hanka Przybylinska IFPAN, Warsaw 33 days 

Francesco Quotchi University of Cagliari, Italy 8 days 

Roland Resel TU Graz 2 days 

Martin Siler Masyryk University Brno 10 days 

Czeslaw Skierbiszewski Unipress, Warsaw 8 days 

Peter Vogronicic TU Bratislava 6 days 

Zbyslaw Wilamowski IFPAN, Warsaw 24 days

62 Personnel Part B: Solid State Physics Group 

Research visits of institute members 

name visit to 

Andrej Andreev ESRF, Grenoble, France 

Michaela Böberl University of Cagliari, Italy 

Wolfgang Heiss University of Surrey, Guildford, UK 

Wolfgang Jantsch Universität Graz 

Universität Amsterdam 

Jürgen Roither University of Surrey, Guildford, UK 

Clemens Simbrunner BESSY, Berlin 

Klaus Schmidegg Department of Microelectronics, TU Bratislava 

Matthias Wegscheider BESSY, Berlin

Part B: Solid State Physics Group Research 63 

Research 

The main scientific activities at the Department of Solid State Physics concern the fabrication, 

characterization and modification of semiconductors, polymers and metals as well as the development 

of novel devices with special focus on Epitaxy, Ion Implantation, Optics and Spectroscopy. 

The materials systems investigated and the available experimental techniques are 

listed below: 

Materials presently under investigation: 

◦ CdSe/CdS, CdTe, HgTe 

◦ Olygomers 

◦ GaN, GaInN, GaAlN, GaN:Fe 

◦ PbTe, EuTe, EuSe 

◦ Si, SiGe 

Experimental facilities and techniques: 

Growth 

◦ Hot wall epitaxy 

◦ Metal organic chemical vapor phase deposition 

◦ Molecular beam epitaxy 

◦ Chemical synthesis 

◦ Seeded growth 

Ex-situ characterization 

◦ Deep level transient spectroscopy 

◦ Fourier spectroscopy 

◦ Electron Spin Resonance 

◦ Transport and photoconductivity measurements 

◦ Ellipsometry 

◦ Reflectance Difference Spectroscopy 

◦ Scanning electron microscopy 

◦ Photoluminescence & Excitation spectroscopy 

In situ characterization 

◦ Reflection difference spectroscopy 

◦ Spectral ellispometry 

◦ X-ray diffraction 

Simulation 

◦ Magnetic phase diagramms 

◦ Air gap cavities

64 Research Part B: Solid State Physics Group


Characterization 


o Spin Relaxation in Zero Dimensional SiGe islands 

o Carrier-induced ferromagnetism in (Ga,Fe)N 

o In situ and real-time characterization of metal-organic chemical vapor deposition 

growth by high resolution x-ray diffraction 

Devices 

o Mid-infrared IV-VI vertical-emitting lasers for 6.7 micron wavelength operating in 

continuous-wave mode 

o Optoelectronic devices based on colloidal HgTe nanocrystals emitting at wavelengths 

between 1.5 and 3.5 µm 

Growth experiments 

o Geometry dependent nucleation mechanism for SiGe islands grown on pit-patterned 

Si(001) substrates 

o Influence of film growth conditions on carrier mobility of Hot Wall Epitaxially grown 

fullerene based transistors

66 Research Part B: Solid State Physics Group 

Spin Relaxation in Zero Dimensional SiGe islands 

H. Malissa, W. Jantsch, G. Chen, T. Fromherz, F. Schäffler, G. Bauer, Z. Wilamowski 1 , 

A. Tyryshkin 2 , S. Lyon 2 

In III-V compounds it was shown that the confinement in low dimensional structures such as 

dots leads to a significant increase of spin lifetimes [1]. In order to achieve confinement in the 

SiGe material system, we grow Ge islands on Si(100) substrates (i) in a self-organized Stranski-Krastanov 

growth mode, which leads to an inhomogeneous distribution of island sizes and 

locations, and (ii) by prepatterning the substrate by either electron beam or holographic lithography. 

In the first type of samples (i) the density of dots is about 5 times higher than in 

the prestructured samples (ii), which we estimate from AFM measurements. The Ge dots were 

overgrown with Si which is locally strained due to the buried Ge dots. The strain causes an 

attractive potential for electrons. Repeating this procedure, Ge dots grow exactly on top of the 

strained Si areas. Up to 12 periods of dots were grown in that way which yielded a total of 

>10 10 dots. 

In photoluminescence experiments a wide band appears around 0.8 eV which corresponds 

to transitions from the valence band of the Ge dots to conduction band states in the strained 

silicon (Fig. 1a). This feature is much stronger in samples with inhomogeneous size distribution 

(i), which can be attributed to the higher dot density. In EPR experiments a sharp line at 

g=1.998 with a line-width of 0.25 G appears under illumination with sub-bandgap light (Fig. 

1b). The amplitude of this signal scales with the estimated total number of spins in the sample 

and also with the PL signal, and is very weak in the structured samples. 

Fig.1: (a) photoluminescence data from structured and unstructured (marked) samples. (b) 

EPR line at g=1.998 with and without illumination with bandgap light. 

The spin relaxation times were measured in time-resolved EPR experiments. In such experiments, 

the sample is not continuously irradiated by microwaves (MW). Instead, short high 

power MW pulses are applied. At resonance, these pulses cause the spins to rotate out of their 

thermal equilibrium orientation parallel to the direction of the static external magnetic field H0 

by an angle that is proportional to the pulse duration around the direction of H1, where H1 the 

value of magnetic component of the MW field. Applying a π/2 pulse causes the spins to rotate 

into the plane perpendicular to the H0, and a π pulse rotates the spins by 180°, thus inverting 

the spin orientation. Interaction with the surrounding lattice (longitudinal relaxation) and with 

other spins (transverse relaxation) causes the spins to dephase and to return to their thermal 

equilibrium value.


Specific pulse sequences are applied in order to observe longitudinal (T1) and transverse 

(T2) relaxation [2,3]. A π/2 pulse puts the overall magnetization in a plane perpendicular to H0 

where it decays due to spin-spin interaction (transverse relaxation) which is observed as free 

induction decay (FID). Some time τ after the first pulse a π pulse is applied in order to rotate 

the spins by 180°. As a consequence, a second FID appears after a time τ, 2τ after the initial 

π/2 pulse (Hahn echo). By varying τ, T2 results from: 

−2τ 

/ T2 

M = M 0e 

where M is the echo amplitude at time t=τ and M0 its value at t=0. 

A π pulse rotates the magnetization into the opposite direction to its thermal equilibrium 

orientation. Due to interaction with the environment the spins will relax back to their initial 

orientation parallel to H0 (longitudinal spin relaxation). After a time T, a π/2 pulse is applied 

to put the magnetization into the plane perpendicular to H0, and a π pulse is used to observe 

the Hahn echo as described above. T1 results from: 

−T 

/ T1 

M = M 0 ( 1 − 2e 

) 

Only the sample containing self-organized dots could be measured with time resolved 

EPR. We obtain a value of 0.8 µs for T2 which is isotropic, whereas T1 depends on sample 

orientation: in the case where H0 is perpendicular to the sample plane, T1 is 0.7 µs; in the case 

where H0 is oriented in-plane, T1 is 1.2 µs which is roughly what one expects for spin orbit 

coupling. Expressed in terms of line width, the homogeneous transverse line width is 0.082 G 

(isotropic) and the longitudinal line width is 0.070 G for perpendicular H0 and 0.022 G for inplane 

H0. For comparison, the inhomogeneously broadened line width from cw EPR is 

0.220 G for perpendicular and 0.350 G for in-plane H0, which is considerably larger than the 

homogeneous contributions. The large inhomogeneous line width is attributed (i) to a fluctuation 

of the g-factor for different dot sizes and (ii) the hyperfine interaction with 29 Si. 

References 

1. M. Kroutvar, Y. Ducommun, D. Heiss, M. Bichler, et al.: “Optically programmable electron spin memory 

using semiconductor quantum dots”, Nature 432, 81 (2004) 

2. A. Schweiger and G. Jeschke: “Principles of Pulse Electron Paramagnetic Resonance” (Oxford University 

Press, Oxford, 2001) 

3. A. M. Tyryshkin, S. A. Lyon, W. Jantsch, and F. Schäffler: “Spin Manipulation of Free Two-Dimensional 

Electrons in Si/SiGe”, Phys. Rev. Lett. 94, 12802 (2005) 


1 

Z. Wilamowski, Institute of Physics, Polish Academy of Sciences, Warsaw, Poland. 

2 

A. Tyryshkin, S. Lyon, Department of Electrical Engineering, Princeton University, Princeton, USA. 

Funding 

FWF, FFF, Land OÖ, Firmen, ÖNB, EU, GME, BMWV, ÖAW, ÖAD, Sparkasse OÖ, etc., 

Corresponding Author: hans.malissa@jku.at


Carrier-induced ferromagnetism in (Ga,Fe)N 

C. Simbrunner, W. Wegscheider H. Sitter, A. Bonanni 

Semiconductor spin transfer electronics (spintronics) represents a key research area with the 

aim of employing rather the spins of single electrons, than their charge for storing, 

transmitting and processing quantum information. The expected advantages of spin devices 

include non-volatility of stored information, higher integration density, lower power operation 

and higher switching speed. It is expected that new functionalities for electronics and 

photonics can be achieved if the injection, transfer and detection of carrier spin can be 

controlled above room temperature. 

A promising family of materials systems for spintronics is represented by diluted magnetic 

semiconductors (DMS). A recent theoretical work [1] was the breakthrough that focused 

attention on nitride-based DMS as being most promising for achieving practical ordering 

temperatures. According to the mentioned theoretical model, itinerant holes are essential for 

the mediation of the long-range ferromagnetic interactions. While most of the theoretical and 

experimental work for DMS materials has focused, to date, on the use of Mn as the magnetic 

dopant, room temperature carrier-mediate ferromagnetism has not yet been achieved and there 

start to be some progress in identifying other transition metal atoms that may be employed to 

trigger the mechanism at practical temperatures. Iron, for example. The value of exchange 

energy, crucial for the onset of carrier-induced mechanism, has been estimated for (Ga,Fe)N 

to be such that ferromagnetism at room temperature can be expected, provided that free holes 

can be introduced. In the frame of the proposed project (officialy started in July 2004), for the 

first time both hexagonal and cubic p-type GaN doped with Fe and grown by means of metalorganic 

chemical vapour deposition will be thoroughly studied in the perspective of achieving 

(or ruling out) room-temperature carrier-mediated ferromagnetism. 

The first six months of the running project have been dedicated to the upgrade of our 

Metal Organic Chemical Vapor Deposition (MOCVD) setup (where the Fe(C5H5)2 source 

necessary for the deposition of magnetic Fe species, has been introduced) and to the optimisation 

of the growth process. Haxagonal-GaN were fabricated on sapphire (0001)-oriented substrates 

according to a well established growth process [2] and a thorough study of Mg-doping, 

including δ- and homogeneous doping, of GaN buffers has been performed. The Fe source 

was calibrated and the first series of GaN:Fe and Mg-GaN(Fe) samples have been completed. 

The deposition process was controlled in-situ via spectroscopic ellipsometry and laser reflectometry. 

High-resolution X-ray diffraction (HRXRD) measurements were routinely performed 

and rocking curves of the GaN(0002) reflex gave a full-width at the half maximum 

(FWHM) ranging from 260 to 320 arcsec depending on the Fe content and comparable with 

state-of-the-art device nitride material. In all the samples doped with mgnetic ions, Fe has 

been found to be homogeneously incorporated. The total Fe concentration in the layers, as 

obtained from secondary ion mass spectroscopy (SIMS), was found to increase with increasing 

growth temperature at a constant source flux as well as with increasing cource flux at constant 

growth temperature. The highest Fe concentration obtained so far was of the order of 

0.2% and further growth optimisation experiments are currently carried out in order to increase 

the efficiency of magnetic-ions incorporation. Electron spin resonance (ESR) experiments 

revealed the presence of non-interacting Fe 3+ (S=5/2) ions substituting Ga in all studied 

GaN samples. The concentration of Fe 3+ estimated from the amplitude of the ESR signal was 

consistently lower than that determined from SIMS measurements. Moreover, the Fe 3+ ESR


signal amplitude was found to increase in samples with the same iron content but increasing 

concentration of Mg acceptors. This indicates that the Fe impurity in GaN may coexist in two 

charge states, Fe 3+ and Fe 2+ . As the ground state of Fe 2+ is not magnetic no ESR signal related 

to this valence state can be observed. However, recharging of those two states can be achieved 

with UV illumination. In the power range where the ESR signal is not saturated a metastable 

decrease of the Fe 3+ signal amplitude is observed and the effect becomes stronger in a sample 

codoped with Mg. This indicates that Mg competes efficiently with Fe 2+ in the capture of 

holes. The Fe 3+ concentration determined by SQUID magnetometry is also consistently lower 

than the total iron concentration seen in SIMS. In addition to the Curie type of paramagnetism 

due to Fe 3+ (d 5 ) a significant temperature independent contribution has been found. 

Magnetization [ emu/cm 3 ] 

0.4 

0.2 

0.0 

-0.2 

-0.4 

250 K 

-0.2 0.0 0.2 

Magnetic Field [ T ] 

(a) 

Fig. 1. Magnetization of a typical GaN:Fe sample as measured at 250 K (trace a), and after substracting the 

contribution linear in magnetic field (trace b). 

(b) 

As shown in Fig.1, the high temperature contribution consists typically of a paramagnetic part 

linear with the magnetic field, and a ferromagnetic component. We attribute the former to van 

Vleck paramagnetism, most likeyl originating from the Fe 2+ (d 6 ) charge state of iron. The origin 

of the ferromagnetic phase is so far unknown. 

References 

1. T. Dietl, H. Ohno, F. Matsukura, J. Cibert, D. Ferrand, Science 287, 1019 (2000). 

2. A. Bonanni, D. Stifter, A. Montaigne-Ramil, K. Schmidegg, K. Hingerl, H. Sitter, J.Cryst.Growth 248, 211, 

(2003). 


1 

W. Jantsch, H. Malissa, Festkörperphysik, Uni Linz; 

2 

H.Krenn, Experimentalphysik, Karl-Franzens Universität, Graz; 

3 

H.Przybylinska,T.Dietl, Institute of Physics, Polish Academy of Sciences, Warsaw, 

Funding 

FWF 

Corresponding Author: alberta.bonanni@jku.at


In situ and real-time characterization of metal-organic chemical vapor 

deposition growth by high resolution x-ray diffraction 

C. Simbrunner, K. Schmidegg, A. Bonanni, H. Sitter, 

A. Kharchenko 1 , J. Bethke 1 , K. Lischka 2 

Metal Organic Chemical Vapor Deposition (MOCVD) is nowadays the most frequently used 

industrial method for growing III-V-nitrides. The possible spectrum of in-situ diagnostic tools 

is quite narrow because MOCVD growth process excludes all techniques based on ultra high 

vacuum conditions. Therefore only optical methods like spectroscopic ellipsometry (SE) and 

X-ray diffraction (XRD) give the possibility to observe and analyse in-situ the growing surface. 

Our previous work showed the successful use of a X-ray diffraction system to analyse the 

MOCVD growth of cubic GaN in-situ [1]. Simultaneous measurement of spectroscopic ellipsometry 

and X-ray diffraction represents an interesting and new combination of in-situ characterization 

techniques which combine surface and bulk sensitivity. 

The reconstruction of our MOCVD reactor enables the simultaneous use of both techniques to 

analyse the growth of hexagonal GaN in-situ. Our setup which is shown in 

Fig. 1(a) has the advantage that neither a goniometer nor exact sample positioning are required 

and it is compact enough to be attached to an industrial-size MOCVD reactor. The Xrays 

(standard Cu X-ray tube) are focused with a Johansson monochromator to the sample 

surface and the reflected beam is analysed with a position sensitive detector. 

a) 

X-ray tube 

Detector 

10° 

Be window 

Johansson 

Monochromator 

Si (333) 

Sample 

Be window 

SE window 

b) 

Intensity [Counts] 

10 2 

10 1 

GaN AlGaN 

10 

100 110 120 130 140 150 160 170 180 190 200 

0 

Position [Pixel] 

Fig.1: a) MOCVD reactor setup for simultaneous use of spectroscopic ellipsometry and 

X-ray diffraction. b) XRD spectra during AlGaN growth 

All growth experiments were performed on sapphire (0001) substrates. Using trimethylgallium 

(TMGa), trimethylaluminum (TMAl), trimethylindium (TMIn) and ammonia (NH3) as 

precursors GaN, AlGaN and InGaN layer were deposited on top of a GaN buffer which was 

grown using standard techniques [2]. The substrate was rotating in the gasflow to increase 

homogeneity. 

Using a special summation algorithm [3] spectra of the GaN ( 1 12 

4) 

reflex were derived and 

fitted with a pseudo voigt function. Fig. 1(b) shows typical results during AlGaN growth. 

About 220 seconds after opening the TMAl source the AlGaN peak becomes visible. This 

corresponds to a layer thickness of about 28nm which is the estimated thickness resolution of 

the X-ray system. The peak position gives information about strain on the one hand and the 

ternary composition on the other hand. Furthermore an increase of the peak intensity is visible 

during growth.


The integrated peak intensities of the measured peaks show a linear dependence as a function 

of layer thickness - Fig. 2(a). This allows to measure in-situ the growth rate which was 

0.125 nm s -1 during AlGaN growth. Due to the overgrowth of the GaN buffer during AlGaN 

growth the integrated peak intensity of GaN decreases linearly as a function of time. 

a) 

prop. integrated intensity 

1200 

1000 

800 

600 

400 

200 

GaN 

AlGaN 

GaN 

AlGaN 

0 

3000 4000 5000 6000 7000 8000 9000 10000 

Time [s] 

b) 

prop. FWHM 

10 

9 

8 

7 

6 

5 

4 

3 

GaN 

AlGaN 

2 

4000 5000 6000 7000 

Time [s] 

8000 9000 10000 

Fig.2: a) Integrated Peak intensity as a function of time. b) FWHM of GaN and AlGaN peak 

as a function of time 

The FWHM of the fitted curves can be correlated to the crystal quality of the grown layer. 

Our measurements show a narrowing of the peaks during growth which is inverse proportional 

to the layer thickness - Fig. 2(b). 

Further growth experiments will be made to improve the system and to collect data to give 

more detailed interpretations. The recent results show that the use of X-ray diffraction 

enlarges the spectrum of possible in-situ characterisation techniques for hexagonal GaN 

MOCVD growth even when using sample rotation to improve homogeneity. 

References 

1. K. Schmidegg, A. Kharchenko, A. Bonanni, H. Sitter, J. Bethke, K. Lischka, „Characterization of MOCVD 

growth of cubic GaN by in situ x-ray diffraction“, J. Vac. Sci. Technol. B., 2, 2165 (2004) 

2. A. Bonanni, D. Stifter, A. Montaigne-Ramil, K. Schmidegg, K. Hingerl, H. Sitter, „In situ spectroscopic 

ellipsometry of MOCVD-grown GaN compounds for on-line composition determination and growth 

control”, J. Crystal Growth, 248, 211-215 (2003) 

3. A. Kharchenko, „A new X-ray diffractometer for the online monitoring of epitaxial processes”, 

dissertation, Univ. Paderborn (2003) 


1 

PANalytical B.V., Almelo, The Netherlands 

2 

Department of Physics, University of Paderborn, Paderborn, Germany 

Funding 

FWF, GME, PANalytical 

Corresponding Author: clemens.simbrunner@jku.at


Mid-infrared IV-VI vertical-emitting lasers for 6.7 micron wavelength 

operating in continuous-wave mode 

T. Schwarzl, J. Fürst 1 , G. Springholz, M. Böberl, E. Kaufmann, J. Roither, H. Pascher 1 , 

W. Heiss 

Coherent optical emitters for the mid-infrared (MIR) are very useful for high-sensitive gas 

analysis. For such devices, the lead salts are well suited because of their favorable band structure. 

Thus, in many MIR spectroscopic applications edge-emitting lead-salt laser diodes are 

used. Alternatively, surface-emitting lead-salt microcavities offer several advantages over 

edge-emitters such as a small beam divergence and single mode operation. Since their first 

demonstration, improvements in design and MBE growth has led to optically pumped IV-VI 

vertical-cavity surface-emitting lasers (VCSELs) with pulsed emission up to 65 °C. 

In the current work, we demonstrate optically pumped continuous-wave (cw) PbSe 

VCSELs exhibiting laser emission around a wavelength of 6.7 µm. The high-finesse microcavity 

laser structures were grown by molecular beam epitaxy (MBE) on BaF2 (111) substrates. 

They are formed by two EuSe/Pb0.94Eu0.06Se Bragg mirrors with high reflectivities exceeding 

99.5 %. The 2λ cavity region between the mirrors includes the 1.4 µm thick PbSe active 

zone. The lasers were pumped by a CO laser at 5.3 µm within the transparent region of 

the Bragg mirrors [1]. 

Figure 1 shows the emission spectra of a VCSEL structure at 85 K above threshold (pump 

power 95 mW, filled squares) and below threshold (pump power 43 mW, open squares, 

strongly enlarged scale). The laser linewidth is smaller than the resolution of our measurement 

setup (< 0.6 nm) with a strong narrowing with respect to the linewidth of the weak subthreshold 

signal. The stimulated emission exhibits a very narrow beam divergence below 1° 

and a large tuning range of 70 nm (see Fig. 2) [2]. The observed cw output power amounts up 

to 1.2 mW at 85 K. Cw laser operation is achieved up to temperatures of 120 K. 

Emission Intensity (rel. u.) 

PbSe 

VCSEL 

above threshold: 

FWHM 0.6 nm 

sub-threshold: 

FWHM 11 nm 

x 2500 

6.67 6.68 6.69 6.70 

Wavelength (µm) 

Figure 1: Emission spectra of a laser structure at 85 K above threshold (filled squares) and 

below threshold (open squares, strongly enlarged scale). The measured linewidth and 

spectrometer resolution (as denoted by -||-) are indicated. The solid lines represent Gaussian 

line fits to the experimental data.


Emission Energy (meV) 

187.0 

186.5 

186.0 

185.5 

185.0 

184.5 

Angular Emission 

0 1 2 3 4 

Divergence Angle θ/2 (°) 

0.058 meV/K 

(2.1 nm/K) 

6.64 

6.66 

6.68 

6.7 

6.72 

60 65 70 75 80 85 90 95 100 105 

Temperature (K) 

Figure 2: Tuning characteristic of the emission wavelength of the VCSEL by temperature 

(filled dots) with a linear tuning coefficient of 0.058 meV/K. The dashed line is a linear fit to 

the data. The inset shows the angular emission of the VCSEL (filled squares) with a sketch of 

the measurement geometry. The solid line is a Gaussian line fit to the experimental data. 

References 

1. J. Fürst, H. Pascher, T. Schwarzl, M. Böberl, G. Springholz, G. Bauer, W. Heiss, “Continuous wave 

emission from midinfrared IV-VI vertical-cavity surface-emitting lasers”, Appl. Phys. Lett. 84, 3268 (2004) 

2. T. Schwarzl, G. Springholz, M. Böberl, E. Kaufmann, J. Roither, W. Heiss, J. Fürst, H. Pascher, “Emission 

properties of 6.7 µm continuous-wave PbSe-based vertical-emitting microcavity lasers operating up to 

100 K”, Appl. Phys. Lett. 86, 031102 (2005) 


1 

J. Fürst, H. Pascher, Experimentalphysik I, Universität Bayreuth, D-95447 Bayreuth, Germany. 

Funding 

FWF, START Project, GME 

Corresponding Author: thomas.schwarzl@jku.at 

Wavelength (µm)


Optoelectronic devices based on colloidal HgTe nanocrystals emitting 

at wavelengths between 1.5 and 3.5 µm 

M. V. Kovalenko, J. Roither, E. Kaufmann, W. Heiss, S. Günes 1 , H. Neugebauer 1 , N. S. Sariciftci 

1 

While bulk HgTe is a zero-gap semiconductor, the band gap of chemically synthesized 

nanocrystals (NCs) from this material offers a huge infrared tuning range strongly depending 

on the particle size. We demonstrate HgTe NCs prepared by an aqueous-based colloidal synthesis 

exhibiting strong photoluminescence at wavelengths between the near infrared and the 

mid-infrared. By the choice of the capping thiol-molecules, which can be changed by a ligand 

exchange procedure, different surface functionalities can be provided. This makes the NCs 

soluble in a variety of different liquids, resulting in a high flexibility for thin film preparation 

and incorporation of NCs in different optoelectronic devices. As examples, we demonstrated 

(a), light emitting microcavity devices operating close to a wavelength of 1.5 µm [1] and (b), 

polymer/nanocrystal hybrid solar cells with an infrared extended photosensitive wavelength 

region. 

(a) The microcavity devices consist of a TiO2/SiO2 Bragg interference bottom mirror on glass 

substrates, followed by the active NC layer, a SiO2 spacer layer and a metallic top mirror. The 

NC layer is assembled by layer-by-layer deposition to obtain densely packed nanocrystal 

films with well controllable thicknesses. The thickness of the spacer layer is varied to tune the 

wavelength of the cavity resonance to the desired target wavelength of 1.5 µm. The emission 

spectra give clear evidence for a single cavity resonance with a linewidth smaller by a factor 

of 8 than that of a NC reference layer (see Fig. 1). The emission of the devices is observed up 

to temperatures above 75 °C and it is strongly forward directed with a beam divergence 

smaller than 3°. 

PL-intensity (normalized) 

wavelength, µm 

2 1,8 1,6 1,4 

reference 

0,6 0,7 0,8 0,9 

photon energy (eV) 

Fig.1: Emission spectra of HgTe NC based micro-cavity devices 

with various cavity lengths compared to the emission of a 

reference layer.


(b) The hybrid solar cells make use of a nanoporous TiO2 layer for electron transport which is 

deposited on indium tin oxide (ITO) covered glass substrates. HgTe NCs for spectral sensitization 

are deposited on the TiO2 by adsorption from aqueous solutions. Poly-3hexylthiophene 

(P3HT) is drop-cast on top of the structure for hole transport. The best photovoltaic 

response is obtained when HgTe NCs are blended into the P3HT layer, in addition to 

the HgTe at the TiO2/P3HT interface. For this kind of cell we achieved an open circuit voltage 

(Voc) of 400 mV, a short circuit current (Isc) density of 1.96 mA/cm 2 and a fill factor of 0.5. 

Most importantly, however, the photoresponse of these solar cells is extended up to a wavelength 

of 1.4 µm (Fig. 2), so that an even larger portion of the solar spectrum is used for energy 

conversion than from a classical Si solar cell. 

IPCE(%) 

10 

8 

6 

4 

2 

0 

P3HT 

glass 

400 600 800 1000 1200 1400 

wavelength (nm) 

Fig. 2: Photon to current efficiency (IPCE) spectrum of a hybrid 

solar cell showing a photoresponse up to 1.4 µm. 

References 

1. J. Roither, M. V. Kovalenko, S. Pichler, T. Schwarzl, W. Heiss, Appl. Phys. Lett. 86, 241104 (2005) 

2. J. Roither, W. Heiss, D. V. Talapin, N. Gaponik, A. Eychmüller, Appl. Phys. Lett. 84, 2223 (2004) 


1 

Linz Institute of Organic Solar Cells (LIOS), Physical Chemistry, University of Linz, 4040 Linz, Austria 

Funding 

FWF (Projects START Y179 and SFB IR-ON), EU Commission (Project Molycell 6th Framework), Council of 

Higher Education Turkey (YÖK), GME, 

Corresponding Author: Wolfgang.Heiss@jku.at 

Au 

HgTe 

TiO 2 

ITO


Geometry dependent nucleation mechanism for SiGe islands grown 

on pit-patterned Si(001) substrates 

Gang Chen, Herbert Lichtenberger, Friedrich Schäffler, Günther Bauer, and 

Wolfgang Jantsch 

We explored the influence of the pit depth on the nucleation mechanism of SiGe islands on a 

pit-patterned substrate. For shallow pit-patterned substrates, we investigated the initial stage 

of the 2D-3D transition of a deposited SiGe layer. We observed the formation of ripple structures 

characterised by {1, 0, 5}/(001) terraces and prisms bounded by {1, 0, 5} facets after 

growth of the SiGe wetting layer, as shown in Figure 1a. These results are attributed to the 

strain-driven step-bunching as well as the step-meandering instability. With further Ge deposition, 

the nucleation of the SiGe islands at the bottom of the pit has been exclusively observed, 

as shown in Figure 1b. 

Fig. 1 (a) AFM image of sample after deposition of 3 ML Ge at a fixed rate of 0.03 Å/s under 

620 o C. (b) AFM image of sample after deposition of 4 ML Ge at a fixed rate of 0.03 Å/s under 

620 o C. 

On the other hand, the growth of SiGe dot arrays with a periodicity down to 250 nm has been 

achieved on deep-pit-patterned Si(001) substrates(see Fig. 2b). In this case, the SiGe dots nucleate 

at the top terrace in between the deep-pits instead of at the bottom of them. Both pyramidal 

and dome-like SiGe islands can be obtained via the control of the growth conditions. 

The sidewalls of the pits have also been reshaped into inverted pyramids and into dome structures 

depending on the amount of the Ge deposited due to the strain driven facet transition 

process. (as shown in Fig. 3)


Fig. 2: Three dimensional view of the AFM images of samples S69 and S11 after Ge/SiGe 

deposition. For sample S69, 7 monolayers of Ge were deposited at 620 o C at a rate of 0.03 Å/s. 

To enhance the migration of the deposited Ge, growth was interrupted for 10s after each ML 

grown. For sample S11, a layer of 35 Å Si55Ge45 was deposited at 650 o C at a rate of 0.2 Å/s 

for Si, and 0.164 Å/s for Ge, respectively. (c) and (d). The height profiles along [110] direction 

(indicated by arrows) are shown in Figs. 2(a) and (b). 

Fig. 3: Three dimensional AFM images with higher resolution for S69 (a) and S11(b), measured 

along [110] directions and [100] directions, respectively. SOM images are given in (c) 

and (d)for S69 and S11, indicating that the surface geometries are dominated by pyramidal 

structures with {1, 0, 5}facets for S69 (c), and dome structures with {1, 0, 5}, {1, 1, 3}, {15, 

3, 23} facets for S11 (d), respectively.


Influence of film growth conditions on carrier mobility of Hot Wall 

Epitaxially grown fullerene based transistors 

H. Sitter, A. Montaigne 

Although the van der Waals type interactions between organic molecules and inorganic substrates 

are rather weak, the crystallographic phases, the orientation, and the morphology of the 

resulting organic semiconductor film critically depends on the interface properties and growth 

kinetics. In turn, the transistor field-effect mobility is largely determined by the morphology 

of the semiconductor film at the interface with the gate dielectric [1]. We have considered 

such interface related phenomena with an attempt by growing C60 semiconductor layers on 

top of organic dielectric divinyltetramethyldisiloxane-bis(benzocyclobutene) (BCB) by hot 

wall epitaxy (HWE) at different substrate temperatures (Ts). 

Figure 1(a) shows an AFM image of a C60 layer deposited, for 15 seconds, on BCB dielectric 

at a Ts very close to room temperature (RT). In this case, elongated grains are observed with 

an arial density of crystallites around 500 crystallites/µm 2 . When the C60 layer is grown on the 

BCB substrate heated at a Ts of 130 0 C, the resulting film has a strikingly different nanomorphology, 

see Figure 1(b). In the latter case, a bigger grain size, a density of crystallites around 

370 crystallites/µm 2 

and more round granules are observed. 

(a) (b) 

Fig.1: AFM images of C60 thin films deposited on BCB dielectric for a period of time equal to 15 

seconds and a substrate temperature of: (a) room temperature, (b) 130 o C. 

Figure 2 shows a scheme of our Organic Field Effect Transistors (OFET’s). The fabrication of 

the OFET’s started by partially etching the indium tin oxide (ITO) on the glass substrate. Afterwards, 

a 2 µm thick BCB layer was deposited by spin coated. The deposition of the 300 nm 

thick C60 films on the BCB dielectric took place in a HWE reactor. The drain and source contacts 

(LiF/Al) were evaporated through a shadow mask. 

Figure 3 shows the square root of the source-drain current ds 

I vs. (Vgs -Vt) for two 

OFET’s based on 300 nm C60 films deposited on BCB dielectric at Ts equal to RT and 130 o C, 

respectively. Vgs and Vt are the gate and onset voltages, respectively. The electron field effect 

mobilities µe increase from 0.5 cm 2 /Vs to 3 cm 2 /Vs as Ts increases. The mobility was evaluated 

by fitting the experimental data to the standard transistor equation [2]. In the estimation 

of the field-effect mobility, we have assumed a Vgs independent mobility and also we have 

not taken into account contact resistances for simplicity. The improvement in the µe is as-


sumed to be due to transition of C60 film morphology at the interface from small elongated 

grains to bigger rounder and closely packed grains as depicted in Figure 1(a) and 1(b). 

Fig.2: Scheme of the n-type C60 field effect transistor. 

Fig.3: I ds vs. (Vgs-Vt) plots for OFET’s based on 300 nm C60 thin films grown on BCB 

dielectric at two different substrate temperatures equal to RT and 130 o C, respectively. 

[1] F. Dinelli, M. Murgia, P. Levy, M. Cavallini, F. Biscarini and D. M. de Leeuw, Phys. Rev.Lett 92, 116802 


[2] S.M.Sze, in : Physics of Semiconductor Devices (Wiley, New York, 1981) 

Main Publications 

1. Th. B. Singh, N. Marjanovic, G. J. Matt, S. Günes, N. S. Sariciftci, A. Montaigne Ramil, A. Andreev, H. 

Sitter, R. Schwödiauer, S. Bauer. “High-mobility n-channel organic filed-effect transistors based on 

epitaxially grown C60 films.” Organics Electronics 6, 105 (2005). 

2. A. Montaigne Ramil, H. Sitter, Th. B. Sing, N. Marjanovic, S. Günes, G. J. Matt, N. S. Sariciftci, A. 

Andreev, T. Haber and R. Resel “Influence of film growth conditions on carrier mobility of hot wall 

epitaxially grown fullerene based transistors.”, Journal of Crystal Growth, submitted. 


√ I ds (√A) 

0 30 60 

Vgs-Vt (V) 

1 S.N. Sariciftci, Linzer Ints. for Organic Solar Cells (LIOS) and Physical Chemistry, Linz University,Linz, A- 

4040, Austria. 2 R.Resel, Inst. of Solid State Physics, TU Graz, Petergasse 16, A-8010 Graz, Austria. 3 A. Andreev, 

Inst. for Physics, University of Leoben, Franz Josef Strasse 18, A-8700 Leoben, Austria. 4 A. Winkler, 

Inst. for Solid State Physics, TU Graz, Petergasse 16, A-8010 Graz, Austria. 

Funding 

FWF and GME 

Corresponding Author: alberto.montaigne@jku.at and Helmut.Sitter@jku.at 

0,02 

0,01 

0,00 

T s = 130 0 C 

T s = RT 

fit to the experimental data 

using the standard transistor 

equation, ref [2] 

V ds =60 V 

µ e ≈ 3 cm 2 /Vs 

µ e ≈ 0.5 cm 2 /Vs

80 Research Part B: Solid State Physics Group

Part B: Solid State Physics Group Diploma and Doctoral Theses 81 

Diploma and Doctoral Theses 

Current diploma theses 

1. Anzengruber Johannes 

“Optische Resonatoren für die Molekülspektroskopie” 

(Supervisor: W. Heiss) 

2. Isfahani Farnaz 

“Fabrication of stamp for nanoimprint lithography using reactive ion etching – Study and 

optimization of the process parameters” 

(Supervisor: K. Hingerl) 

3. Kirchschlager Raimund 

“Magnetooptische Eigenschaften von Eu-Chalcogeniden” 


4. Pichler Stefan 

“Nanokristall basierende elektrooptische Bauteile” 


5. Matthias Wegscheider 

“Growth and optical characterization of nitride-based diluted magnetic semiconductors” 

(Supervisor: H. Sitter) 

Current doctoral theses 

1. Dipl.Ing. Joachim Achleitner 

“Simulation magnetooptischer Effekte in EuTe” 


2. Eugen Baumgartner 

“Optoelectronic devices based on nanocrystals” 


3. Dipl.Ing. Michaela Böberl 

“Electro-optical IV-VI devices for the mid-infrared” 


4. Dipl.Ing. Thomas Glinsner 

“Herstellung von 3D photonischen Kristallen mittels nanoimprint Lithographie” 


5. M.Sc. Roman Holly 

“Fabrication and characterization of fiber to chip light couplers” 

(Supervisor: K.Hingerl) 

6. Mag. Erich Kaufmann 

“Lateral emitting lead-salt microlasers” 

(Supervisor: W. Heiss)

82 Diploma and Doctoral Theses Part B: Solid State Physics Group 

7. Maksym Kovalenko 

“Synthesis and characterization of nanocrystals for the mid infrared” 


8. Dipl.Ing. Hans Malissa 

“Spin properties of low-dimensional systems” 

(Supervisor: W. Jantsch) 

9. Dipl.Ing. Jürgen Roither 

“Light emitting nanodevices: Novel concepts and their realization” 


10. Dipl.Ing. Klaus Schmidegg 

“Growth and optical characterisation of GaN and its ternary compounds” 


11. Dipl.Ing. Clemens Simbrunner 

“MOCVD growth and In-situ characterization of ferromagnetic nitride semiconductors.” 


12. Dipl.Ing Walter Söllinger 

“Monte Carlo simulations of spin-related phenomena in magnetic semiconductor structures” 


13. M.Sc. Javad Zarbakhsh 

“Designing photonic devices in silicon” 


14. Dipl.Ing. Gernot G. Fattinger 

“Acoustic Wave Phenomena in Multilayered Thin Film Layer Stacks” 

(Supervisor: W. Jantsch)

Part B: Solid State Physics Group Publications 83 


Publications 

1. A. Kadashchuk, A. Andreev, H. Sitter, N.S. Sariciftci, Yu. Skryshevski, Yu. 

Piryatinski, I. Blonsky, D. Meissner 

Aggregate states and energetic disorder in highly-ordered nanostructures of parasexiphenyl 

grown by Hot-Wall Epitaxy 

Advanced Functional Mat. 14, 970 (2004), 

2. A. Yu. Andreev, C. Teichert, G. Hlawacek, H. Hoppe, R. Resel, D.-M. Smilgies, H. 

Sitter, N. S. Sariciftci 

Morphology and growth kinetics of organic thin films deposited by hot wall Epitaxy 

Organic Electronics 5, 23-27 (2004) 

3. A. Montaigne, K. Schmidegg, A. Bonanni, H. Sitter, D. Stifter, Li Shunfeng, D. J. As, 

K. Lischka 

In-situ growth monitoring by spectroscopic ellipsometry of MOCVD cubic - GaN 

(001) 

Thin Sol. Films 455-456, 684-687 (2004) 

4. F. Quochi, F. Cordella, R. Orru, J. E. Communal, P. Verzeroli, A. Mura, G. 

Bongiovanni, A. Andreev, H. Sitter, N. S. Sariciftci 

Random laser action in self-organized para-sexiphenyl nano-fibers grown by Hot Wall 

Epitaxy 

Appl. Phys. Lett. 84, 4454-4456 (2004) 


Bauer 

Anisotrophy of g-factor and electron spin resonance linewidth in modulation doped 

SiGe quantum wells 

Appl- Phys. Lett. 85, 1739-1941 (2004) 

Virtual Journ. of Nanoscale Science & Technology-September27 (2004) Vol.10, Issue 

13 (2004) 

6. V. Glukhanyuk, H. Przybylinska, A. Kozanecki, W. Jantsch 

Site Symmetry of erbium centers in GaN 

phys. stat. sol. (A) Applied Research 201 (2), 195-198 (2004) 

7. Z. Wilamowski, W. Jantsch 

Supression of spin relaxation of conduction electrons by cyclotron motion 

Phys. Rev. B 69, 035328 (2004) 

8. Z. Wilamowski, W. Jantsch 

Spin Relaxation of 2D electron in Si/SiGe quantum well suppressed by an applied 

magnetic field 

Semicond. Sci. Technol. 19, 390-391 (2004)

84 Publications Part B: Solid State Physics Group 

9. W. Jantsch, Z. Wilamowski 

Spin Coherence and Manipulation in Si/SiGe Quantum Wells 

in: Frontiers in Molecular-Scale Science and Technology of Nanocarbon, nanoSilicon 

and Biopolymer Multifunctional Nanosystems, Proc. NATO ARW, ed. by E. 

Buzaneva and P. Scharff, 379-390, Kluwer Academic Publishers (2004) 

10. K. Schmidegg, A. Kharchenko, A. Bonanni, H. Sitter, J. Bethke, K. Lischka 

Characterization of MOCVD growth of cubic GaN by in situ X-ray diffraction 

J. Vac. Sci. Technol. B 22 (2004) 

11. A. Andreev, T. Haber, D.-M. Smilgies, R. Resel, H. Sitter, N. S. Sariciftci, L. Valek 

Morphology and growth kinetics of organic thin films deposited by Hot Wall Epitaxy 

on KCl substrates 

J. Cryst. Growth (Proceedings Grenoble) (2004) 

12. A. Bonanni, K. Schmidegg, A. Montaigne Ramil, A. Kharchenko, J. Bethke, K. 

Lischka, H. Sitter 

On-line growth control of MOCVD deposited GaN and related ternary compounds via 

spectroscopic ellipsometry and x-ray diffraction 

Phys. Stat. Sol (a), 201, 2259-2264 (2004) 

13. A. Andreev, F. Quochi, A. Kadaschuk, H. Sitter, C. Winder, H. Hoppe, S. Sariciftci, 

A. Mura, G. Bongiovanni 

Blue emitting self-assembled nano-fibers of para-sexiphenyl grown by Hot Wall 

Epitaxy 

Phys. Stat. Sol. (a), 201, 2288-2293 (2004) 

Conference on Photo-Responsive Materials, Kariega, South Africa, Febr. 25-29 

(2004) 

14. E. Belas, P. Moravec, R. Grill, J. Franc, A. L. Toth, H. Sitter, P. Höschl 

Silver diffusion in p-type CdTe and (CdZn)Te near room temperature 

Phys. Stat. Sol. (c) 1, 929-932 (2004) 


Bauer 

Bychkov-Rashba effect and g-fractor tuning in modulation doped SiGe quantum wells 

Acta Phys. Pol. 105, 585 (2004) 

16. O. M. Fedorych, Z. Wilamowski, W. Jantsch, J. Sadowski 

Electrically detected magnetic resonance 

Acta Phys. Pol. A 105 (6), 591-598 (2004) 

17. Kazuto Koike, Isao makabe, Mitsuaki Yano, Erich Kaufmann, Wolfgang Heiss, 

Gunther Springholz, Michaela Böberl 

Molecular Beam Epitaxial Growth and Photoluminescence Characterization of 

PbTe/CdTe Quantum Wells for Mid-Infrared Optical Devices 

Journ. of the Society of mat. science, japan, 53,1328-1333 (2004) 

18. T. Gurung, S. Mackowski, H. E. Jackson, L. M. Smith, W. Heiss, J. Kossut, G. 

Karzewski


Optical studies of zero-field magnetization of CdMnTe quantum dots: Influence of 

average size and composition of quantum dots 

J. Appl. Phys. 96, 7407 (2004) 

19. M. Böberl, T. Fromherz, T Schwarzl, G. Springholz, W. Heiss 

IV-VI resonant cavity enhanced photodetectors for the mid-infrared 

Semicond. Sci. Technol. 19, L115 (2004) 

20. J. Fürst, T. Schwarzl, M. Böberl, H. Pascher, G. Springholz, W. Heiss 

Continuous wave and pulsed emission from a vertical cavity surface emitting laser in 

the 8 m midinfrared spectral range 

IEEE J. of Quantum Electronics 40, 9197 (2004) 

21. J. Fürst, H. Pascher, T. Schwarzl, M. Böberl, G. Springholz, G. Bauer, W. Heiss 

Continuous wave emission from a midinfrared IV-VI vertical-cavity surface-emitting 

laser 

Appl. Phys. Lett. 84, 3268 (2004) 

22. T. A. Nguyen, S. Mackowski, H. E. Jackson, L. M. Smith, J. Wrobel, K. Fronc, G. 

Karczewski, J. Kossut, M. Dobrowolska, J. K. Furdyna, W. Heiss 

Resonant spectroscopy of II-VI self-assembled quantum dots: Excited states and 

exciton-longitudinal optical phonon coupling 


23. R. Kirchschlager, W. Heiss, R. T. Lechner, G. Bauer, G. Springholz 

Hysteresis loops of the energy band gap and effective g-factor up to 18000 for 

metamagnetic EuSe epilayers 


24. J. Roither, W. Heiss, D. V. Talapin, N. Gaponik, A. Eychmüller 

Highly directional emission from colloidally synthesized nanocrystals in vertical 

cavities with small mode spacing 


25. T. A. Nguyen, S. Mackowski, H. E. Jackson, L. M. Smith, G. Karczewski, J. Kossut, 

M. Dobrowolska, J. Furdyna, W. Heiss 

Exciton-LO phonon interaction in II-VI self-assembled quantum dots 

Phys. Stat. Sol. (c) 1, 767 (2004) 

26. T. Gurung, S. Mackowski, H. E. Jackson, L. M. Smith, W. Heiss, J. Kossut, G. 

Karczewski 

Tuning the optical and magnetic properties of II-VI quantum dots by post-growth 

rapid thermal annealing 

Phys. Stat. Sol. (b) 241, 652 (2004) 

27. W. Heiss, R. Kirchschlager, G. Springholz, Z. Chen, M. Debnath, Y. Oka 

Magnetic polaron induced near-bandgap luminescence in epitaxial EuTe 

Phys. Rev. B 70, 035209 (2004)


28. S. Mackowski, G. Prechtl, W. Heiss, F. V. Krychenko, G. Karczewski, J. Kossut, M. 

Dobrowolska, J. K. Furdyna 

Impact of carrier redistribution on the photoluminescence of quantum dot ensembles 


29. D. Kuritsyn, A. Kozanecki, H. Przybylínska, W. Jantsch 

Energy transfer to Er 3+ ions in silicon-rich-silicon oxide: Efficiency limitations 

Phys. Stat. Sol. C: Conferences 1 (2) , 229-232 (2004) 

submitted 2004 / in print 

1. H. Malissa, Z. Wilamowski, W. Jantsch 

Cyclotron resonance revisited: the effect of carrier heating 

Proc. ICPS-27, in print 

2. A. Kharchenko, K. Lischka, K. Schmidegg, H. Sitter, J. Bethke, J. Woitok 

In-situ and real time characterization of MOCVD growth by high resolution x-ray 

diffraction 

Scientific Instruments, in print 

3. K. Schmidegg, G. Neuwirt, H. Sitter, A. Bonanni 

Simultaneous determination of composition and growth rate of MOCVD-growth 

ternary nitride compounds by multiple wavelength spectroscopic ellipsometry 

J. Cryst. Growth (Proceedings Grenoble), in print 

4. D. Franta, I. Ohlidal, P. Klapetek, A. Montaigne-Ramil, A. Bonanni, D. Stifter, H. 

Sitter 

Optical properties of ZnTe films prepared by molecular beam epitaxy 

Thin Sol. Films, in print 

5. M. Siler, I. Ohlidal, D. Franta, A. Montaigne-Ramil, A. Bonanni, D. Stifter, H. Sitter 

Optical characterization of double layers containing epitaxial ZnSe and ZnTe films 

Journ. of Mod. Optics, in print 

6. H. Malissa, D. Gruber, D. Pachinger, F. Schäffler, W. Jantsch, Z. Wilamowski 

Demonstration of g-factor tuning in a SiGe double quantum well device 

superlattices and microstructures, submitted 

7. H. Przybylínska, G. Kocher, W. Jantsch, D. As, K. Lischka 

Photoconductivity study of Mg and C acceptors in cubic GaN 

Proc. ICPS-27, in print 

8. W. Jantsch, H. Malissa, Z. Wilamowski, H. Lichtenberger, G. Chen, F. Schäffler, G. 

Bauer 

Spin properties of electrons in low dimensional SiGe structures 

PASPS Proceedings, in print


9. G. Hobler, L. Palmetshofer 

Ion Implantation 

Vacuumelectronic Components and Devices, ed. J. Eichmeier, M. Thumm, in print 

10. G. Otto, G. Hobler, L. Palmetshofer, K. Mayerhofer, K. Piplits, H. Hutter 

Dose-Rate Dependence of Damage Formation in Si by N Implantation as Determined 

from Channeling Profile Measurement 

Nucl. Instr. Meth. B, accepted 

11. K. Mayerhofer, H. Foisner, K. Piplits, G. Hobler, A. Burenkov, L. Palmetshofer, H. 

Hutter 

Range Evaluation in SIMS Depth Profiles of Er Implantations in Silicon 

Appl. Surf. Sci., accepted 

12. A. Bonanni, K.Schmidegg, H. Sitter, D. Stifter 

In-situ multiple wavelength ellipsometry for real time processcharacterization of nitride 

MOCVD 

Proceedings of the ICPS27, in print 

13. K. Schmidegg, H. Sitter, A. Bonanni 

In-situ optical analysis of low temperature MOVCD GaN nucleation layer formation 

via multiple wavelength ellipsometry 

J.Cryst.Growth, in print 

14. J. Roither, M. V. Kovalenko, S. Pichler, T. Schwarzl, W. Heiss 

Nanocrystal based microcavity light emitting devices operating in the telecommunication 

wavelength range 

Appl. Phys. Lett. 

15. S. Mackowski, T. Gurung, H. E. Jackson, L. M. Smith, W. Heiss, J. Kossut, G. 

Karczewski 

Sensitivity of Exciton Spin Relaxation in quantum dots to Confining Potential 


16. T. Schwarzl, M. Böberl, G. Springholz, E. Kaufmann, J. Roither, W. Heiss, J. Fürst, 

H. Pascher 

Molecular beam epitaxy of vertical-cavity microcavity lasers for the 6-8 µm spectral 

range operating in continuous-wave mode 

J. of Crystal Growth 

17. T. Schwarzl, G. Springholz, M. Böberl, E. Kaufmann, J. Roither, W. Heiss, J. Fürst, 

H. Pascher 

Emission properties of 6.7 µm continuous-wave PbSe-based vertical-emitting microcavity 

lasers operating up to 100 K 


18. J. Fürst, H. Pascher, T. Schwarzl, G. Springholz, M. Böberl, G. Bauer, W. Heiss 

Magnetic field tunable circularly polarized stimulated emission from midinfrared VI- 

VI vertical emitting lasers 

Appl. Phys. Lett.


19. A. Kozanecki, D. Kuritsyn, W. Jantsch 

On the role of Yb as an impurity in the excitation of Er 3+ emission in silicon-rich silicon 

oxide 

Mat. Science Engineering C (ELSEVIER publisher) in print 

20. H. Malissa, W. Jantsch, G. Chen, D. Gruber, H. Lichtenberger, F. Schäffler, Z. 

Wilamowski, A. Tyryshkin, S. Lyon 

Investigation of the Spin Properties of Electrons in Zero Dimensional SiGe Structures 

by Electron Paramagnetic Resonance 


21. G. Chen, H. Lichtenberger, F. Schäffler, G. Bauer, W. Jantsch 

Geometry dependence of nucleation mechanism for SiGe islands grown on pitpatterned 

Si(001) substrates 


22. H. Przybylínska, A. Bonanni, A. Wolos, M. Kiecana, M. Sawicki, T. Dietl, H. Malissa, 

C. Simbrunner, M. Wegscheider, H. Sitter, K. Rumpf, P. Granitzer, H. Krenn, W. 

Jantsch 

Magnetic properties of a new spintronic material – GaN:Fe 


23. A. M. Tyryshkin, S. A. Lyon, W. Jantsch, F. Schäffler 

Spin Manipulation of free 2-dimensional electrons in Si/SiGe quantum wells 

Cond-Mat/0304284 

Phys. Rev. Lett. 94, 126802-1.4 (2005) 

April 11, 2005 issue of Virtual Journ. of Nanoscale Science & Technology 

April 2005 issue of Virtual Journ. of Quantum Information FWF, GMe, ÖAD 

Book chapters 

1. G. Springholz, T. Schwarzl, W. Heiss, 

Mid-infrared Vertical Cavity Surface Emitting Lasers based on the Lead Salt Compounds 

to be published in „Mid-infrared Optoelectronics“, Editor: A. Krier, Springer,

Part B: Solid State Physics Group Talks and Presentations 89 

Invited Talks 


H. Sitter, A. Andreev, C. Teichert, G. Hlawacek, T. Haber, D. Smilgies, R. Resel, A. Montaigne-Ramil, 

S. Sariciftci 

Organic thin films grown by Hot Wall Epitaxy on inorganic substrates 

XVII Latin American Symposium on Solid State Physics 

06.-09.12.2004, Habana, Cuba 

W. Jantsch, Z. Wilamowski 

Spin properties of conduction electrons in Si/SiGe quantum wells 

SiGeNET Final Meeting- Research Training Network Contract HPRN-CT-1999-00123 

02.-03.02.2004, University of Linz, Austria 

W. Jantsch, Z. Wilamowski 

Properties and manipulation of electron spins in low dimensional SiGe structures 

International Workshop Spintronics: Spin injection, Transport and Manipulation, 

11.-12.10.2004, Ruhr-Universität Bochum, Germany 


A. Andreev, F. Quochi, H. Hope, H. Sitter, S. Sariciftci, A. Mura, G. Bongiovanni 

Blue emitting self-assembled nanocrystals of para-sexiphenyl grown by Hot Wall Epitaxy 

5 th Int.Conf. on Low Dimensional Structures and Devices 

12.-17.12. 2004, Cancun – Mexico 

M. Oehzelt, T. Haber, A. Andreev, H. Sitter, D. Smilgies, J. Kecks, R. Resel 

Epitaxial growth of sexiphenyl on KCl(100)-performance of reciprocal space maps 

7 th Biennial Conference on High-Resolution X-ray Diffraction 

07.-10.09.2004, Prag, Czech Republic 

R. Resel, O. Lengyel, T. Haber, M. Oehzelt, S. Mülleger, A. Winkler, B. Winter, G. Koller, 

M. Ramsey, G. Hlawacek, C. Teichert, A. Andreev, H. Sitter 

Formation and Structure of oligo-phenyl thin films for organic opto-electronics 

Workshop on Compound Semiconductor Devices and Integrated Circuits 

17.-19.05.2004, Smolenice, Slovakia 

T. Haber, M. Oehzelt, D. Smilgies, W. Grogger, B. Schaffer, H. Sitter, A. Andreev, R. Resel 

Epitaxial Growth of sexiphenyl Thin Films on KCl(100) 

International Conference on Surface Science 

28.06.-02.07.2004, Venice, Italy 

R. Resel, M. Ramsey, G. Koller, C. Teichert, A. Andreev, H. Sitter 

Foramtion of Sexiphenyl Nanofibers by Epitaxial Growth on Dielectric Substrates 

324 th WE-Heraeus Seminar, Exploring the nanostructures of Soft Materials with X-rays 

10-12.05.2004, Bad Honnef, Germany

90 Talks and Presentations Part B: Solid State Physics Group 

F. Quochi, A. Andreev, F. Cordella, R. Orru, A. Mura, G. Bongiovanni, H. Hope, H. Sitter, S. 

Sariciftci 

Low-threshold blue lasering in nanocrystals of para-sexiphenyl grown by Hot-Wall Epitaxy 

International Conference on Synthetic Metals 

28.06.-2.07.2004, Wollongang, Australia 

K. Schmidegg, A. Kharchenko, A. Bonanni, K. Lischka, H. Sitter, J. Bethke 

In-Situ determination of growth-rate and concentration of ternary MOCVD nitrides via multiple 

wave-length ellipsometry 

12 th International Conference on Metal Organic Vapor Phase Epitaxy 

30.05.-04.06.2004, Lahaina, Maui, Hawaii, USA 

A. Bonanni, K. Schmidegg, A. Montaigne-Ramil, A. Kharchenko, J. Bethke, K. Lischka, H. 

Sitter 

On- line growth control of MOCVD deposited GaN and related ternary compounds via spectroscopic 

ellipsometry and x-ray diffraction 

Conference on Photo-Responsive Materials 

25.-29.02.2004, Kariega, South Africa 

A. Andreev, F. Quochi, H. Hope, H. Sitter, S. Sariciftci, A.Mura, G. Bongiovanni 




A. Andreev, H. Hope, T. Haber, D. Smilgies, H. Sitter, S. Sariciftci, R. Resel 

Highly Oriented Organic Semiconductor Thin Films Grown by Hot Wall Epitaxy on Different 

Substrates 

5 th International Conference „Electronic Processes in Organic Materials“ (ICEPOM-5) 

24.-29.05.2004, Kiew, Ukraine 

A. Andreev, F. Quochi, T. Haber, H. Hope, D. Smilgies, H. Sitter, S. Sariciftci, R. Resel, A. 

Mura, G. Bongiovanni 

Morphology and growth kinetics of organic thin films deposited by Hot Wall Epitaxy on KCl 

and NaCl substrates 

14 th International Conference on Crystal Growth 

09.-13.08.2004, Grenoble, France 



5 th Int.Conf. on Low Dimensional Structures and Devices 

12.-17.12. 2004, Cancun – Mexico


M. Oehzelt, T. Haber, A. Andreev, H. Sitter, D. Smilgies, J. Kecks, R. Resel 

Epitaxial growth of sexiphenyl on KCl(100)-performance of reciprocal space maps 

7 th Biennial Conference on High-Resolution X-ray Diffraction 

07.-10.09.2004, Prag, Czech Republic 

R. Resel, O. Lengyel, T. Haber, M. Oehzelt, S. Mülleger, A. Winkler, B. Winter, G. Koller, 

M. Ramsey, G. Hlawacek, C. Teichert, A. Andreev, H. Sitter 

Formation and Structure of oligo-phenyl thin films for organic opto-electronics 

Workshop on Compound Semiconductor Devices and Integrated Circuits 

17.-19.05.2004, Smolenice, Slovakia 

T. Haber, M. Oehzelt, D. Smilgies, W. Grogger, B. Schaffer, H. Sitter, A. Andreev, R. Resel 

Epitaxial Growth of sexiphenyl Thin Films on KCl(100) 

International Conference on Surface Science 

28.06.-02.07.2004, Venice, Italy 

R. Resel, M. Ramsey, G. Koller, C. Teichert, A. Andreev, H. Sitter 

Foramtion of Sexiphenyl Nanofibers by Epitaxial Growth on Dielectric Substrates 

324 th WE-Heraeus Seminar, Exploring the nanostructures of Soft Materials with X-rays 

10-12.05.2004, Bad Honnef, Germany 

F. Quochi, A. Andreev, F. Cordella, R. Orru, A. Mura, G. Bongiovanni, H. Hope, H. Sitter, 

S.Sariciftci 

Low-threshold blue lasering in nanocrystals of para-sexiphenyl grown by Hot-Wall Epitaxy 

International Conference on Synthetic Metals 

28.06.-2.07.2004, Wollongang, Australia 

K. Schmidegg, A. Kharchenko, A. Bonanni, K. Lischka, H. Sitter, J. Bethke 

In-Situ determination of growth-rate and concentration of ternary MOCVD nitrides via multiple 

wave-length ellipsometry 

12 th International Conference on Metal Organic Vapor Phase Epitaxy 

30.05.-04.06.2004, Lahaina, Maui, Hawaii, USA 

A. Bonanni, K. Schmidegg, A. Montaigne-Ramil, A. Kharchenko, J. Bethke, K. Lischka, H. 

Sitter 

On-line growth control of MOCVD deposited GaN and related ternary compounds via spectroscopic 

ellipsometry and x-ray diffraction 







A. Andreev, H. Hope, T. Haber, D. Smilgies, H. Sitter, S. Sariciftci, R. Resel 

Highly Oriented Organic Semiconductor Thin Films Grown by Hot Wall Epitaxy on Different 

Substrates 

5 th International Conference „Electronic Processes in Organic Materials“ (ICEPOM-5) 

24.-29.05.2004, Kiew, Ukraine




Morphology and growth kinetics of organic thin films deposited by Hot Wall Epitaxy on KCl 

and NaCl substrates 

14 th International Conference on Crystal Growth 


W. Jantsch, H. Malissa, Z. Wilamowski, H. Lichtenberger, G. Chen, F. Schaeffler, G. Bauer 

Spin properties of electrons in low dimensional SiGe structures, 

21.-23.07.2004, PASPS III, Santa Barbara, Ca, USA 

H. Malissa, W. Jantsch, M. Muehlberger, F. Schaeffler, Z. Wilamowski, 

Bychkov-Rasba Effect in low dimensional SiGe structures 

26.-30.07.2004, 27 th Int. Conference on the Physics of Semiconductors, Flagstaff Arizona, 

USA 

Z. Wilamowski, H. Malissa, W. Jantsch 

Cyclotron resonance revisited: the effect of carrier heating 


USA 

H. Przybylinska, R. Buczko, G. Kocher, W. Jantsch, D. As, K. Lischka, 

Photoconductivity study of Mg and C acceptors in cubic GaN 


USA 

H. Malissa, W. Jantsch, M. Mühlberger, F. Schäffler, Z. Wilamowski, M. Draxler, P. Bauer 

Spin relaxation and g-factor tuning in low dimensional SiGe structures 

28.-30.09.2004, 54. Jahrestagung der Österreichischen Physikalischen Gesellschaft, Linz, 

Austria 

H. Przybylinska, G. Kocher, W. Jantsch, D. As, K. Lischka, R. Buczko 

Mg and C acceptors in cubic GaN studied by photothermal ionization spectroscopy 


Austria 

H. Malissa, Z. Wilamowski, W. Jantsch 

Cyclotron resonance in high mobility Si: the effect of carrier heating 


Austria 

O. M. Fedorych, Z. Wilamowski, W. Jantsch, J. Sadowski 

Electrically detected magnetic resonance 

28.05.-04.06.2004, XXXIII International School on the Physics of Semiconducting 

Compounds, Jaszowiec, Poland


H. Malissa, W. Jantsch, M. Mühlberger, F. Schäffler, Z. Wilamowski, M. Draxler, P. Bauer 

Bychkov-Rashba effect and g-factor tuning in modulation doped SiGe quantum wells 

28.05.-04.06.2004, XXXIII International School on the Physics of Semiconducting 

Compounds, Jaszowiec, Poland 

A. Andreev, T. Haber, D. M. Smilgies, L. Valek, R. Resel, H. Hope, H. Sitter, S. Sariciftci 

Mophology and growth kinetics of organic thin films deposited by Hot Wall Epitaxy on different 

substrates, poster at the Jahrestaung der ÖPG 

01.06.2004, Linz, Austria 

A. Bonanni, K. Schmidegg, H. Sitter, 

In-situ multiple wave-length ellipsometry: virtual-interface approximation model for simultaneous 

determination of growth-rate and composition in MOCVD nitrides, poster at the 14 th 

International Conference on Crystal Growth 


J. Liday, I. Hotovy, H. Sitter, K. Schmidegg, A. Bonanni, P. Vogrincic 

NiO-based contacts for blue emitting diodes, poster at the International Conference on Inorganic 

New Materials 

September 2004, Antwerp, Belgium 



Epitaxial Growth of Blue Emitting Organic Nano-Wires, poster at the 13 th International Conference 

on Molecular Beam Epitaxy 

22.-27.08.2004, Edingburgh, England 

A. Bonanni, D. Stifter, K. Hingerl, H. Sitter, K. Schmidegg 

In-situ multipel wavelength ellipsometry for real time process characterization of nitride 

MOCVD 

27 th International Conference on the Physics of Semiconductors (ICPS27) 

July 2004, Flagstaff 

K. Schmidegg, H. Sitter, K. Hingerl, A. Bonanni 

In-Situ optical analysis of low-temperature MOCVD GaN nucleation layer formation via multiple-wavelength 

ellipsometry 

12 th Intenational Conference on Metal Organic Chemical Vapor Deposition (ICMOVPE12) 

June 2004, Lahaina (Hawaii) 

G. Springholz, T. Schwarzl, J. Fürst, M. Böberl, H. Pascher, W. Heiss 

Vertical-cavity surface-emitting lasers with cw emission at long wavelength of 6-8 microns 

2004 MRS Fall Meeting 

29.11.-3.12.2004, Boston, MA 

W. Söllinger, R. Kirchschlager, G. Springholz, W. Heiss, K. Rumpf, H. Krenn 

3D Monte Carlo simulatiuon of the magnetic phase diagram of EuTe epilayers 

Nano and Giga Challenges in Microelectronics 

Symposium and Summer School 

13.-17.09.2004, Cracow, Poland


G. Springholz, T. Schwarzl, E. Baumgartner, W. Heiss 

Molecular beam epitaxy of wide/narrow band gap semiconductors for mid-infrared broadband 

Bragg mirrors and high finesse microcavities 

13 th Int. Conf. on Molecular Beam Epitaxy (MBE 2004) 

22.-27.08.2004, Edinburgh, Scotland 

T. Schwarzl, J. Fürst, M. Böberl, H. Pascher, G. Springholz, W. Heiss 

MBE growth of vertical-emitting microcavity lasers for the 6-8 micron spectral range operating 

in continuous-wave mode 

13 th Int. Conf. on Molecular Beam Epitaxy (MBE 2004) 

22.-27.08.2004, Edinburgh, Scotland 

R. Kirchschlager, W. Heiss, R. T. Lechner, G. Bauer, G. Springholz 

Hysteresis loops of the energy band gap and effective g-factor up to 18000 for metamagnetic 

EuSe layers 

27 th Int. Conf. on the Physics of Semiconductors, ICPS 

26.-30.07.2004, Flaggstaff, Arizona 

M. Böberl, T. Schwarzl, G. Springholz, W. Heiss, J. Fürst, H. Pascher 

Bleisalzverbindungen für optische Bauelemente im mittleren Infraroten 

34. Infrarot Kolloquium 

20.-21.04.2004, Freiburg, Germany 

T. Schwarzl, J. Fürst, M. Böberl, H. Pascher, G. Springholz, W. Heiss 

Contiuous-wave emission from vertical-cavity surface-emitting lasers at long wavelengths 

between 6 and 8 microns 

6 th Int. Conf. on Mid-Infrared Optoelectronics Materials and Devices, MIOMD 6, 28.06.- 

01.07.2004, St. Petersburg, Russia 

E. Kaufmann, W. Heiss, G. Springholz, M. Böberl, T. Schwarzl 

Contiuous-wave light emission from PbTe based heterostructures with CdTe or PbEuTe barriers 

6 th Int. Conf. on Mid-Infrared Optoelectronics Materials and Devices, MIOMD 6, 

28.06.-01.07.2004, St. Petersburg, Russia 

E. Baumgartner, T. Schwarzl, G. Springholz, W. Heiss 

Omnidirectional laser-quality Bragg mirrors with broad stop bands in the mid-infrared 

6 th Int. Conf. on Mid-Infrared Optoelectronics Materials and Devices, MIOMD 6, 28.06.- 

01.07.2004, St. Petersburg, Russia 

W. Heiss, J. Roither, K. Hingerl, S. Andreeva 

Waveguiding effects in layer by layer deposited films of chemically synthesized CdTe 

nanocrystals 

E-MRS 2004 Spring Meeting 

24.-28.05.2004, Strasbourg, France


J. Roither, W. Heiss, V. Talapin, N. Gaponik, A. Eychmüller, 

Highly directional emission from colloidally synthesized nanocrystals in vertical cavities with 

small mode spacing 

E-MRS 2004 Spring Meeting 

24.-28.05.2004, Strasbourg, France 

E. Kaufmann, W. Heiss, G. Springholz, M. Böberl, T. Schwarzl, M. Yano, I. Makabe, K. 

Koike 

Continuous wave midinfrared photoluminescence of IV-VI and IV-VI/II-VI heterostructures 

13 th Int. Winterschool on New Developments in Solid State Physics 

15.-20.02.2004, Mauterndorf, Austria 

M. Böberl, W. Heiss, T. Schwarzl, G. Springholz, Z. Wang, K. Reimann, M. Woerner 

Dynamics of lead-salt microcavity lasers after femtosecond optical excitation 

13 th Int. Winterschool on New Developments in Solid State Physics 

15.-20.02.2004, Mauterndorf, Austria

96 Funded Research Projects Part B: Solid State Physics Group 

Funded Research Projects 

Projects funded by “Fonds zur Förderung der Wissenschaftlichen 

Forschung (FWF)” (Austrian Science Foundation) 

1. P15816-N08 

“Magnetische Exzitonen in Eu-Chalcogenid Heterostrukturen” 

13. May 2002 - 31. aug. 2006 

Project leader: W. Heiß 

2. F 2505-N08 

“Nanocrystals for mid-infrared photonics” 


01. March 2005 – 29. Febr. 2009 


3. P16631-N08 

“Spin Eigenschaften in niedrig-dimensionalen Halbleitersystemen” 

01.December 2003 – 01.December 2006 

Project leader: W. Jantsch 

4. P 15872-N08 

“Modeling of Ionimplantation Inducent Damage in Silicon” 

15. Feb. 2003 - 14. Feb. 2006 

Project leader: G. Hobler (TU Wien) 

Experimental part performed at JKU: L. Palmetshofer 

5. P15155-THP 

“Lichtunterstütztes Wachstum von organischen Filmen” 

December 1 st 2001- November 30 th 2004 

Project leader: H. Sitter 

6. P15627-THP 

“Hoch geordnete Dünnfilme aus kleinen Molekülen” 

October 1 st 2002 – September 30 th 2004 

Project Leader: H. Sitter 

7. P17169-N08 

“Carrier-induced ferromagnetism in GaN(Fe)” 

July 1 st 2004 – June 30 th 2006 

Project leader: A. Bonanni

Part B: Solid State Physics Group Funded Research Projects 97 

Projects funded by ”Bundesministerium für Verkehr, Innovation 

und Arbeit” 

START-Preis, Projekt Nr. Y179 

“Nanobauteile für Einzelmolekül-Spektroskopie im mittleren Infrarot” 

1. July 2002 - 31. June 2008 

W. Heiß 

Projects funded by “British Council - Academic Research 

Collaboration Program” 

“Development and improvement of novel electro-optical nano-devices based on leadchalcogenides” 

1. Dec. 2003 – 31. May 2004 


Projects funded by “ÖAD ” 

Project no. 6/2004, Wissenschtl.-technische Zusammenarbeit Österreich-Polen “Optical and 

magnetic properties of dopants in GaN and related materials” 

Coord.: W. Jantsch 

Extramural Activities 

Wolfgang Jantsch was elected as member of the executive board of the European Materials 

Research Society. Facts about this institution can be found at: http://www-emrs.cstrasbourg.fr/index.html. 

He was also member of the program committee of the27th International Conference on the 

Physics of Semiconductors, held in Flagstaff, Arizona, July 26-30.

98 Industrial Collaborations Part B: Solid State Physics Group 

Industrial Collaborations 

1. Philips Analytical, Almelo, NL 

2. Siemens AG, Corporate Technology, Materials & Manufacturing 

Innovative Electronics, Erlangen, Germany 

3. W.L. Gor & Associates GmbH 

Putzbrunn, Germany 

4. InfraTec GmbH, Infrarotsensorik und Messtechnik 

Dresden, Germany

Part C 

Christian Doppler Laboratory 

for Surface Science Methods 

(CDLOOM)

Part C: CD Laboratory Personnel 101 

Personnel 

The scientific staff at Christian Doppler Laboratory for Surface Science Methods is solely 

paid by research grants: 

Head 


Kurt Hingerl Doz. Dr. Head of the CDLOOM 



Elke Heissl DI CDG: (01/2004 –09/2004) 

Roman Holly DI CDG: (09/2004 –12/2004) 

Thomas Glinsner DI 

Javad Zarbakhsh DI CDG: (01/2004 –12/2004) 

Post docs 


Dr. Gudrun Kocher Dr. CDG: (01/2004 –12/2004) 


name 

Islam Aynul 

Martin Huber 

Farnaz Isfahani 

graduated 

Technical staff 

name 

Christine Hasenfuss, DI (FH) 

funding 

CDG: (01/2004 – 12/2004)

102 Research Reports Part C: CD Laboratory 


• Processing SOI material for 2D Photonic Crystal Applications by use of Electron 

Beam Lithography 

• Designing and Simulating disordered Photonic Crystals and Geometric Freedom plots

Part C: CD Laboratory Research Reports 103 

Processing SOI material for 2D Photonic Crystal Applications by 

use of Electron Beam Lithography 

Christine Hasenfuß, Kurt Hingerl 

Typical techniques known from semiconductor processing were used for processing 2D 

Photonic Crystal (PhC) devices - particularly Electron Beam Lithography (EBL) and Reactive 

Ion Etching (RIE). 

The first step in solving this task was to produce holes in a Silicon on Insulator (SOI) material. 

These holes should have a diameter of ~300nm and a depth of ~350nm with best 

achievable steepness of the side-walls. To obtain reproducibility the number of processing 

steps should be minimized. 

Corresponding to these demands the first approach was made by using the E-Beam- 

Photoresist directly as an etching mask for RIE. First experiments showed that the selectivity 

resist-substrate during the etching process required a resist-thickness of at least 400nm. This 

resist-thickness was quite challenging as for the needed full exposure depth the dose had to be 

increased. Caused by this high dose an increase in diameter of the exposed structures followed, 

both for the exposure with dots and as areas. In addition the exposure by using dots a 

change in resist properties due to overexposure. (s. Fig. 1) 

Fig.1: The left picture shows AFM-data of an exposed resist pattern where the exposure dose 

is increasing in the diagonal from the left lower dot to the right upper one. The right upper 

picture shows the cross-cut along the diagonal of the rectangle, where the resist is already 

overexposed and changed to negative behaviour (tip-growing in the center of the hole). The 

left lower picture shows the first full exposed dot and the problem of the sidewall steepness. 

The experiment showed that the shape of the walls is very well transferred during the etching 

process. As the obtained steepness of the walls was unfavourable the approach of using 

dot-exposure was laid aside. Exposing a cicular area we expected a better distribution of the 

dose, but the wall-shape of the 400nm thick resist was still not very promising (cones with a 

bottom diameter of 100nm and a top diameter of 380nm were reached). 

The next approach was to use an Al mask for the etching process. After several trials an Al 

layer of 10nm thickness was evaporated on the SOI, so that the thickness of the e-beam resist 

could be decreased from 400nm down to 80nm. The transfer of structure to the Al layer was


done by wet chemical etching in a mixture of KOH and DI water (ratio of 1:300). The selectivity 

of this etching step is very high. And as only the bottom diameter of the holes is transferred 

the wallshape of the exposed resist is no longer of importance! After the RIE step the 

Al layer can easily be removed with HCl. As we achieving a convenient etching mask, some 

experiments on getting appropriate etching parameters were done. Although this work is still 

in progress, first results are presented in Fig.2. 

Fig.2a: Topview of etched holes in SOI-substrate, the reason for the angular shape has to be 

further investigated, but most probably it is caused by the etching process. 

Fig.2b: Sideview on etched holes the SOI with a bottom diameter of 770nm and a top 

diameter of 970nm. 

By optimizing the etching parameters for less isotropic etching, cylindric holes instead of 

cones should be obtained. Furthermore the size of the holes has to be decreased down to 

~300nm. To follow up the goal of a 2D-PhC device, the 2D crystal will be written in a 

waveguide – which is processed by photolithography. After achieving first 2D Photonic Crystals 

devices, simulation results should be verified. 

Funding 

Photeon Technologies GmbH, Christian Doppler Gesellschaft 

Corresponding Author: Christine.Hasenfuss@jku.at

Part C: CD Laboratory Research Reports 105 

Designing and Simulating disordered Photonic Crystals and Geometric 

Freedom plots 

Javad Zarbakhsh, Kurt Hingerl 

In order to study the design flexibility of photonic bandgap structures we investigate different 

examples of 1D, 2D and 3D structures as traditional Bragg layers, 2D photonic crystals, 

and 3D woodpile structures. It turns out that in systems with large gaps evanescent waves 

penetrate into the bulk only distances comparable to one lattice constant, therefore confinement 

of light can also be achieved without long range order, which leads to the introduction of 

novel photonic bandgap designs. Adhering to some constraints the changes in the photonic 

bandgap in disordered structures are negligible. The important quantity to characterize the 

presence respectively absence of modes is the local photonic density of states, however bandgap 

phenomena in size and position disordered arrangements can also be verified with plane 

wave supercell calculations as well as finite difference time domain techniques. We present to 

which extent PC designs can be flexible- still preserving a photonic bandgap with a favorable 

bandgap width. A procedure is proposed for calculating the amount of allowed size changes 

with which one still obtains mode confinement. Starting from well known bandgap maps for a 

given period, which show the range of radii exhibiting a bandgap, we turn the usual argumentation 

upside down: 

Provided that, the penetration depth is small, we ask which set of radii/distances gives 

a bandgap at chosen frequency? The resulting equi-contour plot for the gap in the radius/period 

plane, is what we call "single frequency geometric freedom contour plot" (GFCP) 

(see fig.1 for E polarization and rods.). By sampling points within these GFCPs, we are able 

to compare mode confinement and transmission properties of periodic PCs and non-periodic 

PCs. Applying this procedure in a creative way leads us to new and fancy PC structures. Converting 

the gap map into a GFCP for 1.54 µm vacuum wavelength yields a rather high possible 

variation for pairs of radius/period, exhibiting a bandgap of at least 30%. In this example 

the radius can be varied between 150 nm to 250 nm and the period between 400 nm and 720 

nm. Again, due to the small penetration depth λenv many pairs can be used to design a stop 

band. 

Fig.1: GFCP for the 2 dimensional system of an 

hexagonal array of silicon rods in air at 1.54 µm. 

Fig.2: Transmission for E-polarization through a) 

Bent hexagonal array of silicon rods and b) perfect 

hexagonal array of silicon rods in air.


Photonic crystal slabs in silicon on insulators are the most mature material systems using 

index confinement in the vertical direction. Therefore it is also interesting to investigate the 

purely 2D case of air holes in Si for H-polarization. The lower inset in Fig. 3 shows the gap 

map, the upper one the schematic structure. A large bandgap of 50% exists when the holes 

almost touch (2r/a » 0.85) each other. Furthermore, a wide range of radius/period pairs exist 

retaining a large bandgap of 30%. Here, the situation in the GFCP is reversed: Small holes 

must be nearer than thick holes to keep the bandgap at the same frequency. Choosing points 

out of the 30% area, we construct a new arrangement of a VSPBGS. The arrangement is locally 

hexagonal as shown in fig. 4 and this structure exhibits large bandgap around λ=1.54 

µm. 

Fig.3: GFCP for the 2 dimensional system of an 

hexagonal array of silicon holes (upper inset). The 

lower inset shows the “usual” band gap map. 

Hexagonal array of air holes in silicon b) Bend 

arrangement of hexagonal array, designed to have 

bandgap for 1.54 µm c) Transmission through the 

both arrangements. 

Publications: 

[1] “The finite difference time domain method as a numerical tool for studying the polarization 

optical response of rough surfaces” B. Lehner, K. Hingerl, Thin Solid Films 455, 462, (2004) 

[2] “Polarization Splitting Based on Planar Photonic Crystals”, V. Rinnerbauer, J. Schermer, K. 

Hingerl, Proceedings of ECOC 2004, Stockholm 

[3] “Arbitrary angle waveguiding applications of two-dimensional curvilinear-lattice photonic 

crystals”; J. Zarbakhsh. F. Hagmann, S. F. Mingaleev, K. Busch,-K, und K. Hingerl Appl. Phys. 

Lett., 84, 4687, (2004) 

[4] J. Chaloupka, J. Zarbakhsh, K. Hingerl, Phys. Rev. B, accepted for publication 

Funding 

Photeon Technologies GmbH, Christian Doppler Gesellschaft 

Corresponding Author: kh@jku.at

Part C: CD Laboratory Publications 107 


Publications 

1. B.Lehner, K. Hingerl 

“The finite difference time domain method as a numerical tool for studying the polarizationoptical 

response of rough surfaces” 

Thin Solid Films, 455, 462 

2. L.F.Lastras-Martinez, R. E. Balderas-Navarro, A. Lastras-Martinez and K. Hingerl 

“Stress-induced optical anisotropies measured by modulated reflectance” 

Semic. Sci. and Techn., 19, R35 

3. M.Svaluto Moreolo, K.Hingerl, G. Cincotti 

“Ultra compact 2-D photonic crystal add-drop multiplexer” 

ICTON conference proceedings 

4. J.Zarbakhsh. F. Hagmann, S. F. Mingaleev, K. Busch,-K, K. Hingerl 

“Arbitrary angle waveguiding applications of two-dimensional curvilinear-lattice 

photonic crystals” 

Appl. Phys. Lett., 84, 4687 

5. Javad Zarbakhsh, Kurt Hingerl, Frank Hagmann, Sergei F. Mingaleev, Kurt Busch 

“Curvilinear Photonic Crystals” 

Proceedings of the Opt, Soc. Meeting, Rochester, NY. 

6. V.Rinnerbauer, J. Schermer, K. Hingerl 

„Polarization demultiplexer with Photonic Crystals” 

Proceedings of European Conference on Optical Communication, ECOC 2004 Stockholm 

accepted 2004 

1. J. Chaloupka, J. Zarbakhsh, K. Hingerl 

“Local density of states and modes in circular photonic crystal cavities” 

Phys. Rev. B

108 Talks and Presentations Part C: CD Laboratory 



European Conference of Optical Communication, 8. 9. 2004, Stockholm, Veronika Rinnerbauer: 

“Polarization Splitting realized with Photonic Crystals” 

Bad Honnef, 28. 4. 2004, Workshop on Photonic Crystals, poster presented by Javad Zarbakhsh: 

“Arbitrary angle waveguiding applications of two-dimensional curvilinear-lattice 


ICPS, Flaggstaff, Arizona, 2 posters, 30. 7. 2004 

a) “Reflectance modulated spectroscopy of cubic semiconductors under stress: a tool for 

piezo optical characterization”, A. L. Martinez, L. F. Martinez, R. Balderas Navarro, K. 

Hingerl 

b) “Photoconductivity study of Mg and C acceptors in cubic GaN” H. Przybylinska, R. 

Buczko, G. Kocher-Oberlehner, W. Jantsch, D. As, K. Lischka. 

Talks at universities 

K. Hingerl, 8.1. 2004: Kolloquiumsvortrag: „Zerstörungsfreie optische Messverfahren für die 

Materialcharakterisierung während der Herstellung von dünnen Schichten“ 

J. Zarbakhsh: 23. 3. 2004, Walter Schottky Institut München, Gruppe Prof. J. Finley: “Arbitrary 

angle waveguiding applications of two-dimensional curvilinear-lattice photonic crystals” 

J. Zarbakhsh, 19. 5. 2004: Univ. Würzburg, Institut Prof. Forchel: “Curvilinear-lattice 


Visiting Researchers 


Mag. Michela Svaluto Univ. Roma III (01/2004- 07/2004)

Part C: CD Laboratory Research Projects 109 

Research Projects 

o project with Land Vorarlberg, WISTO GmbH, Dr. Helmut Steurer: „Consulting of 

Vorarlberg Companies on Nanotechnology and Material Science“ (01/2004-10/2004) 

o European Community CRAFT Project “3D Nanoprint” Contract N° : COOP-CT- 2004 - 

512667 (11/2004-10/2006). 

CDL-JKU acts in this EC project as one of the following partners: 

a) micro resist technology GmbH, b) SENTECH Instruments GmbH, c) Heptagon Oy, d) 

Brown&Sharpe Precizika, e) EV Group, E. Thallner GmbH, f) PROFACTOR Produktionsforschungs 

GmbH, g) CDL-JKU, h) Kaunas Universisty of Technology, i) Friedrich 

Schiller Universität Jena.

110 Research Projects Part C: CD Laboratory

Part D 

Lehre, Seminare und Symposia 

– 

Teaching, Seminars, and Symposia

112 Winter Semester 2003/2004 Part D: Teaching 

Winter Semester 2003/2004 

Teaching 

LVA No. Title Type held by 

322.006 Praktikum Halbleiterphysik I PR 3 H. Sitter 

G. Springholz 

Tutor zum PR E. Wintersberger 

322.009 Praktikum Nanotechnologie I PR 2 J. Stangl 

M. Hohage 

322.060 Fortgeschrittenenpraktikum PR 4 W. Heiß 

T. Fromherz 

K. Piglmayer 

M. Hohage 

Tutor zum PR M. Simma 

M. Böberl 

N.N. 

N.N. 

322.028 Grundlagen der Physik III VO 4 G. Bauer 

Tutor zu VO W. Schwinger 

322.031 Übungen zu Grundlagen Physik III UE 2 J. Stangl 

(2 Gruppen) T. Fromherz 

322.043 Übungen zu Grundlagen Physik III 

für LA-Kandidaten 

UE 1 T. Fromherz 

322.074 Festkörperphysik für LA- 

Kandidaten u. Biophysiker 

VO 2 G. Brunthaler 

322.099 Übungen zu FK-Ph. für LA- 

Kandidaten u. Biophysiker 

UE 1 G. Brunthaler 

322.200 Physikal. Messverfahren I VO 2 L. Palmetshofer 

322.066 Kristallwachstum I VO 2 H. Sitter 

322.132 Grundpraktikum III PR 2 A. Bonanni 

322.040 Halbleiterbauelemente 

(Grundlagen) 

VO 2 F. Schäffler 

322.079 Halbleiterphysik f. Fortgeschrittene VO 3 F. Schäffle 

322.112 Physik niedrigdimensionaler 

Systeme 

VO 2 G. Brunthaler 

322.134 Festkörperphysik VO 4 W. Jantsch 

Tutor zur VO H. Malissa 

322.135 Arbeitsgemeinschaft Festkörperphysik UE 2 A. Bonanni 

AG .. Arbeitsgemeinschaft PR .. Praktikum SE .. Seminar 

KO .. Konversatorium PV .. Privatissimum UE .. Uebung 

VO .. Vorlesung

Part C: Teaching Winter Semester 2003/2004 113 


322.114 Charakterisierung v. 

Mikro- u. Nanostrukturen 

VO 2 G. Springholz 

322.115 Übung zu Charakterisierung v. 

Mikro- u. Nanostrukturen 

UE 1 G. Springholz 

322.137 Nanoelektronik, Nanooptik 

u. Nanosensorik II 

VO 2 W. Heiß 

322.136 Nanostrukturen (MEMS & NEMS) SE 2 L. Palmetshofer 

322.095 Ausg. Kapitel aus d. FK-Physik VO 2 V. Holy 

322.103 Privatissimum f. Diplomanden 

u. Dissertanten aus HL- u. FK-Physik 

(Englisch) 

PV 2 G. Bauer 



(Englisch) 

PV 2 H. Heinrich 

322.096 Besprechung neuerer Arbeiten 

in der Festkörperphysik (Englisch) 

SE 2 H. Heinrich 


in der Halbleiterphysik (Englisch) 

SE 2 G. Bauer 

322.105 Privatissimum für Diplomanden 


(Englisch) 

PV 2 W. Jantsch 



(Englisch) 

PV 2 L. Palmetshofer 



(Englisch) 

PV 2 H. Sitter 


u. Dissertanten (Opt. Nanostrukturen) 

(Englisch) 

PV 2 W. Heiß 



(Englisch) 

PV 2 F. Schäffler 



(Englisch) 

PV 2 G. Brunthaler 

322.110 Privatissimum f. Diplomanden PV 2 G. Springholz 


(Englisch) 



VO .. Vorlesung

114 Summer Semester 2004 Part D: Teaching 

Summer Semester 2004 


322.082 Praktikum II aus Halbleiterphysik PR 6 H. Sitter 

G. Springholz 

G. Brunthaler 

Tutor zum PR K. Schmidegg 

322.060 Fortgeschrittenenpraktikum PR4 W. Heiß 

T. Fromherz 

K. Piglmayer 

M. Hohage 

M. Böberl 

M. Simma 

G. Langer 

322.202 Grundlagen der Physik IV VO 2 W. Jantsch 

Tutor zu VO B. Lindner 

322.203 Übungen zu Grundlagen der Physik IV UE 2 J. Stangl 

T.Fromherz 

322.020 Übungen zu Grundlagen der Physik IV 

für LA-Kandidaten 

(WF) 

UE 1 J. Stangl 

322.116 Ausgewählte Kapitel aus der 

Halbleiterphysik: 

Si-basierte Heterostrukturen 

VO 2 F. Schäffler 

322.201 Physikalische Meßverfahren II VO 2 L. Palmetshofer 

322.138 Kristallwachstum II VO 2 H. Sitter 

322.139 Festkörperspektroskopie I VO 2 W. Heiß 

322.089 Herstellung von Mikro- und Nanostrukturen 

VO 2 A. Bonanni 

322.123 Grundlagen der Halbleiterphysik VO 3 F. Schäffler 

322.124 Grundlagen der Halbleiterphysik UE 1 F. Schäffler 

322.129 Physik für Chemiker VO 3 L. Palmetshofer 

Tutor zur VO H. Malissa 



VO .. Vorlesung

Part D: Teaching Summer Semester 2004 115 


322.130 Physik für Chemiker UE 1 G. Springholz 

322.013 Halbleiterhetero- und 

Quantumwellstrukturen VO 2 G. Brunthaler 

322.081 Seminar aus Halbleiterphysik SE 2 A. Bonanni 

322.091 Seminar aus Festkörperphysik: 

Synchrotronstrahlung für die SE 2 J. Stangl 

Materialforschung G. Bauer 

322.000 Elektronenmikroskopie VO 2 F. Schäffler 

322.011 Elektronenmikroskopie PR 1 M. Ratajski 

322.111 Einführung in die Nanotechnologie VO 2 G. Bauer 

D. Bäuerle 

W. Heiß 

M. Hohage 

F. Schäffler 

G. Springholz 

P. Zeppenfeld 

322.096 Besprechung neuerer Arbeiten in 

der Festkörperphysik 

(Englisch) 

SE 2 H. Heinrich 

322.098 Besprechung neuerer Arbeiten in der 

Halbleiterphysik 

(Englisch) 

SE 2 G. Bauer 


u. Dissertanten 

(Englisch) 

PV 2 G. Bauer 



(Englisch) 

PV 2 H. Heinrich 



(Englisch) 

PV 2 W. Jantsch 



(Englisch) 

PV 2 L. Palmetshofer 



VO .. Vorlesung

116 Summer Semester 2004 Part D: Teaching 



(Englisch) 

PV 2 H. Sitter 




(Englisch) 

PV 2 F. Schäffler 



(Englisch) 

PV 2 G. Brunthaler 



(Englisch) 

PV 2 G. Springholz 



(Optische Nanostrukturen, englisch) 

PV 2 W. Heiß 



VO .. Vorlesung

Part D: Teaching Winter Semester 2004/2005 117 

Winter Semester 2004/2005 


322.002 Praktikum I aus Halbleiterphysik PR 2 T. Fromherz 

H. Sitter 

322.009 Praktikum aus Nanotechnologie I PR 2 T. Berer 

M. Hohage 

322.060 Fortgeschrittenenpraktikum PR 4 J. Stangl 

W. Heiß 

M. Hohage 

L. Sun 

K. Piglmayer 

322.069 Grundlagen der Physik I VO 4 W. Jantsch 

322.070 Übungen zu Grundlagen der Physik I UE 2 H. Malissa 

A. Bonanni 

322.071 Übungen zu Grundlagen der Physik I 

für LA-Kandidaten UE 1 H. Malissa 

J. Stangl 

322.074 Festkörperphysik f. Lehramt 

und Biophysik VO 2 G. Brunthaler 

322.099 Übungen zu Festkörperphysik f. 

Lehramt und Biophysik UE 1 G. Brunthaler 

322.132 Grundpraktikum III PR 2 A. Bonanni 

H. Sitter 

322.080 Tieftemperaturphysik VO 2 L. Palmetshofer 

322.140 Digitale Signalverarbeitung für Physiker VO 2 T. Fromherz 

322.126 Mesoskopische Effekte VO 2 G. Brunthaler 

322.040 Halbleiterbauelemente Grundlagen VO 2 L. Palmetshofer 

322.079 Halbleiterphysik für Fortgeschrittene VO 3 F. Schäffler 

322.102 Halbleiterbauelemente für die opt. 

Nachrichtenübertragung VO 2 K. Hingerl 

322.112 Physik niedrigdimensionaler Systeme 

(low-dimensional systems) VO 3 G. Bauer 

322.114 Charakterisierung von Mikround 

Nanostrukturen VO 2 G. Springholz 

322.115 Übungen zu Charakterisierung 

von Mikro- und Nanostrukturen UE 1 G. Springholz 

322.001 Seminar aus Nanoscience and 

-technology SE 2 W. Heiß 



VO .. Vorlesung

118 Winter Semester 2004/2005 Part C: Teaching 



aus Festkörper- u. Halbleiterphysik SE 2 W. Jantsch 


aus Festkörper- u. Halbleiterphysik SE 2 G.Bauer 


u. Dissertanten aus Halbleiter- und 

Festkörperphysik (Englisch) PV 2 G. Bauer 


u. Dissertanten aus Halbleiter- und 

Festkörperphysik (Englisch) PV 2 W. Jantsch 


u. Dissertanten aus Halbleiterund 

Festkörperphysik (Englisch) PV 2 L. Palmetshofer 



Festkörperphysik (Englisch) PV 2 H. Sitter 



Festkörperphysik (Englisch) PV 2 F. Schäffler 



Festkörperphysik (Englisch) PV 2 G. Brunthaler 



Festkörperphysik (Englisch) PV 2 G. Springholz 


u. Dissertanten: Optische 

Nanostrukturen (Englisch) PV 2 W.J. Heiß 



VO .. Vorlesung

Part D: Teaching Seminar Talks 119 

Semiconductor Physics Seminar Talks 

Date Talk 

14.01.2004 Dr. Bärbel Krause, ESRF Grenoble: 

“Shape, Ordering and Strain in InAs/GaAs Quantum Dot Molecules” 

13.02.2004: Prof. Wlodek Zawadzki, Polish Academy of Sciences, Warsaw: 

“Spin splitting of energy subbands due to inversion asymmetry in heterostructures 

– a review” 

03.03.2004: Dr. T. H. Metzger, ESRF Grenoble: 

“Nanostructures in the light of synchrotron radioation” 

29.04.2004 Prof. Prof. Vaclav Holy, Masaryk University Brno and Charles University Prague: 

“Diffuse x-ray scattering from relaxed epitaxial layers” 

03.05.2004 Dr. Wladimir Kaganer, Paul-Drude-Institute for Solid State Electronics: 

“Strain-mediated phase coexistence in MnAs heteroepitaxial films on GaAs” 

24.05.2004 Dipl. Phys. Jens Fürst, Universität Bayreuth: 

“Hanle-Effect measurements in InAs self-assembled quantum dots” 

13.09.2004 Prof. Dr. Sigurd Wagner, Princeton University: 

“Mechanical stress in thin-film devices on thin-polymer substrates” 

07.10.2004 Prof. Wlodek Zawadzki, Polish Academy of Sciences, Warsaw: 

“Zitterbewegung and its effects on electrons in semiconductors” 

28.10.2004 Doz. Dr. Oliver G. Schmidt, MPI f. Festkörperforschung, Stuttgart: 

“From island nucleation to three-dimensional quantum dot crystals” 

11.11.2004 Prof. Dr. Dieter Weiss, Universität Regensburg: 

“Ferromagnet-Halbleiter-Nanostrukturen” 

22.11.2004 Prof. Dr. Jonathan Finley, Technische Universität München: 

“Control of Charges, Spins and Photons using quantum dots” 

13.12.2004 Prof. Dr. Gerald Bastard, Ecole Normale Supérieure Paris: 

“Electron-Phonon Interaction in Quantum Dots” 

16.12.2004 Prof. Dr. Alois Krost, Institut für Experimentelle Physik, Universität Magdeburg: 

“Gallium-Nitrid Heteroepitaxie auf Silizium: vom 3D-Keim zum Bauelement”

Annual Report 2004 - Institut für Halbleiter - JKU

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