The Fraunhofer Institute for Solar Energy Systems ISE and the Materials Research Center FMF at the University of Freiburg have made a groundbreaking advancement in the field of renewable energy. The research team has achieved a new world record efficiency of 15.8% for an organic solar cell with an area of one square centimeter, surpassing their own previous record set in September 2020.

Led by Dr. Uli Würfel, department head at Fraunhofer ISE and group head at the Materials Research Center FMF, the researchers credit the improvement to the application of an anti-reflection coating. This coating enables higher light absorption in the photoactive layer of the cell, resulting in a significant increase in current generation.

Prof. Dr. Andreas Bett, Institute Director at Fraunhofer ISE, highlights the institute’s cross-thematic collaboration as a key strength. By fostering in-house research on different photovoltaic technologies and manufacturing processes, Fraunhofer ISE achieves remarkable results and encourages synergy effects.

The thin-film system used in the record-breaking solar cell was developed in-house using a sputtering process. Fraunhofer ISE is leveraging this coating technology not only for reflection reduction but also for the development of electrodes in semi-transparent organic solar cells. These cells allow visible light to pass through while reflecting near-infrared light back into the solar cell for absorption and conversion into electricity.

Organic solar cells offer numerous advantages, such as being manufactured without heavy metals and other critical elements, lightweight and mechanical flexibility, and ease of integration. Additionally, these cells are aesthetically homogeneous even when semi-transparent. The research team aims to further improve organic solar cells’ transparency by investigating potential materials for the absorber layer and front and rear electrodes.

The accomplishment of the Fraunhofer Institute brings hope for the widespread adoption of organic photovoltaics, which could open new areas of application for solar energy, including transparent solar cells for windows and protective covers for crops.

As researchers worldwide work towards improving the scalability and efficiency of organic solar cells, Fraunhofer Institute’s breakthrough sets a new standard in clean energy technology. The institute’s continuous dedication to sustainable energy solutions showcases its commitment to building a greener future for generations to come.