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

Cell prototyping (CSEM): CSEM has established organic layer deposition by spinning, ink-jetting (cf.
figure 3), screen printing as well as hot-embossing of 3D structures as part of an EU-project
(“ROLLED”) on roll-to-roll OLED fabrication. The printing challenges arise with viscosity constraints,
interface roughness, thickness non-uniformity etc. and lead to a reduction of the record efficiencies
compared to spin-coated devices.
Performed work and achievements
At the kick-off meeting in November
2008 in Winterthur the project
partners presented their institutes /
companies and the first results in
material tailoring and simulation
results have been discussed.
First simulation results
The calculation of optical-electromagnetic-field
penetration spectrum
can be seen in figure 3 (top). This
plot shows the square of the
electromagnetic field inside the
device. This gives a hint of the actual
optical intensity inside the device.
This device has an additional spacer
layer (ZnO) which does not absorb
any light [2,3]. From this calculation
the photon absorption profile can be
calculated which is shown in figure 4
(bottom).
As a next step one can calculate the
maximum achievable short circuit
current Isc,max by summing up the
amount of absorbed photons in the
active layer (P3HT:PCBM). The
knowledge of this is important to tune
the thickness of a device to increase
the short circuit current.
APOLLO, B. Ruhstaller, ICP ZHAW
Figure 3: Optical Field penetration spectrum (top) and calculated
photon absorption spectrum (bottom).
138/290
4/5