New World Record Efficiency for Organic Solar Modules

A member of the research team dressed in lab coat, specs and gloves is holding one of the new investigated organic solar modules. The solar module can be described as a metallic square plate. In the interior it’s blue with metallic vertical lines.
Source: ZAE / Kurt Fuchs

A research team from Nuremberg and Erlangen has set a new record for the power conversion efficiency of organic photovoltaic modules (OPV). The scientists from i-MEET, ZAE and HI ERN in cooperation with South China University of Technology (SCUT), designed an OPV module with an efficiency of 12.6 percent on an area of 26 square centimeters. The new world record exceeds the previous one of 9.7 percent by 30 percent.

This efficiency of 12.6 percent is the highest value ever reported for an organic photovoltaic module. It was confirmed by a certified calibrated measurement under standard test conditions by the independent certification laboratory of Fraunhofer ISE (Freiburg) in September 2019. The multi-cell module was developed at the “Solar Factory of the Future” at Energie Campus Nürnberg (EnCN) in a coating laboratory with a unique megawatt pilot line for thin-film photovoltaics, which was designed and implemented with the financial support of the Bavarian Ministry of Economic Affairs.

Measurement of the organic record solar module performed by the independent certifi- cation laboratory of Fraunhofer ISE (Freiburg)

“This breakthrough shows that Bavaria is not only a leader in the expansion of photovoltaic installations, but also occupies a leading position in the development of future technologies,” emphasizes Hubert Aiwanger, Bavarian State Minister of Economic Affairs, Regional Development and Energy.

Organic solar cells usually consist of two different organic components possessing the necessary semiconductor properties. In contrast to conventionally used silicon, which is manufactured by energy intensive melting processes, organic materials can be applied from solutions directly onto a carrier film or glass carrier.

On the one hand, this reduces manufacturing costs and, on the other hand, the use of flexible, lightweight materials enables new applications, for example in mobile devices or clothing, even if the efficiency is not yet comparable to that of traditional silicon solar cells.

“This milestone in research on organic semiconductors shows that the latest performance developments with certified cell efficiencies of over 16 percent are not limited to the laboratory scale, but can already be scaled up to the level of prototype modules,” explains Prof. Christoph J. Brabec.

Due to their design, the efficiency of complete photovoltaic modules is always somewhat lower than that of individual cells. Part of the module area, for example, is always inactive, since this area is used to interconnect the individual cells. With increased module area, the losses caused by the electrical resistance of the electrodes also increase.

The record module consists of twelve cells connected in series and has a geometric fill factor (GFF) of over 95 percent. This part of the module area actively contributes to the power generation. With respect to its active area, the module even achieves 13.2 percent efficiency. The minimization of inactive areas was achieved by means of high-resolution laser structuring, as developed and optimized in recent years at the “Solar Factory of the Future”.

Technical data:

Module area: 26.129 cm² (± 0.026 cm2)
Power conversion efficiency (PCE): 12.60 % (± 0.19 %)
Open-circuit voltage (Voc): 9.978 V (± 0.04 V)
Short-circuit current (Isc): 46.43 mA (± 0.65 mA)
Fill factor (FF): 71.06 % (± 0.38 %)
Interconnection: 12 cells in series
Geometric fill factor (GFF): 95.5 %
PCE with respect to the active area of the module: 13.2 %