Programm Photovoltaik Ausgabe 2009 ... - Bundesamt für Energie BFE

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Fig.19: a) Kinetics of light-induced degradation for two single-junction a-Si:H p-i-n cells, for open circuit,
short circuit and maximum power point conditions. Results are displayed as relative efficiencies
(i.e. efficiency at time t over initial efficiency). Green points represent the degradation
of the a-Si:H/a-Si:H tandem for comparison.
b) Picture of the inside part of the new laser system installed in Dec. 08 at IMT.
5.3 Laser scribing
A new versatile state-of-the-art lasering setup, whose specifications were defined together with an
industrial partner, is been ramped at IMT. The system is equipped state-of-the-art laser sources All
necessary wavelengths will be available (355, 532 and 1064). It should allow efficient and fast patterning
of the P1, P2, and P3 scribes. The system will allow us to use either a movable beam or a movable
sample for sizes up to 50x60 cm 2 . Its flexibility will make the system a powerful tool to work with a
variety of laser sources and optics, at high speed.
Collaboration and synergies with other projects
Regular academic contacts/scientific and sample exchanges are maintained throughout the project
both with national (CRPP-EPFL, EMPA, HE-Arc,..) and international entities (NREL in Golden, Colorado,
University of Ljubljana, University of Patras, IPV Juelich, Academy of Science of Prague, ECN….).
IMT continues to be involved into the European projects ATHLET and successfully concluded the
FLEXCELLENCE project in October 08. IMT is also involved in the Swiss CCEM-CH Thin film PV
project and in two other EU projects. A strong synergy is or could be realized between all these projects
and this running SFOE project. National collaborations with industrial partners are ongoing, either
in the frame of CTI projects or through direct mandates, e.g. with OC Oerlikon and VHF-Technologies,
3S and Pasan.
Finally IMT was one of the main organiser of the symposium “Light Management in Photovoltaic Devices
-Theory and Practice” at the spring MRS meeting 2008 in San Francisco, which encountered a
very favourable echo in the PV community.
Evaluation for 2008 / perspectives for 2009
In 2008, most of the quantitative targets for the first year described at the beginning of this report could
be reached (or some are close to be achieved such as 8.3% instead of 8.5% stable for tandem a-Si/a-
Si on glass). High initial efficiencies above 13.1% could be reported on glass, as well as more than
10% on glass but for n-i-p structures. Also two patents on innovative device structures could be applied
for.
In 2009, several new fabrication tools will come in line and a major effort will be undertaken to improve
further the processes, their reproducibility, and the materials quality. These systems should allow a
faster device fabrication cycle time, with less process to process variability and should replace the
generations of manual equipment at IMT. In parallel, in 2009 a major effort towards the realisation of
superstrates and substrates ideal for the growth of micromorph cells will be undertaken, base on the
replication processes or on innovative glass/TCO structures.
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New processes and device structures for the fabrication of high efficiency thin film silicon photovoltaic modules, C. Ballif, University of Neuchâtel