41% efficient solar cell wins award for Fraunhofer Scientist
German scientist, Dr.Frank Dimroth of the Fraunhofer Institute for Solar Energy Systems ISE in Freiburg is awarded with the “Fondation Louis D” award, the most prestigious French science award.
This unique solar cell, grown by MOVPE on a germanium substrate, offers nearly double the efficiency of conventional Si-based solar cells and is composed of a metamorphic triple-junction. To accomplish 41% efficiency, Dr. Dimroth and his team created the III-V compound semiconductor device by stacking three different single-junction cells on top of each other.
Each single-junction cell is particularly efficient in converting a limited spectral bandwidth of sunlight to electricity. In order to ensure that the solar cells are better adapted to the spectrum of waves found in sunlight, a wide range of III-V compounds were metamorphically grown.
“I am extremely pleased for my team and the entire Institute in light of this outstanding research prize and the international recognition it brings for our work,” Dr. Dimroth commented. “This prize shows us once again that we are on the right track toward developing solar technologies. Concentrator systems have the potential to supply Southern Europe with low-cost solar electricity in a matter of just a few years. With our work we are tackling an important task for the future.”
The wafer-thin solar cell structure just a few µm thick, has a well-hidden complex inner structure of up to 50 monocrystalline layers. The photovoltaic (PV) concentrator module employs Fresnel lenses to concentrate solar radiation by a factor of 500 onto triple-junction solar cells of 3 square millimeters.
Prof. Eicke R. Weber, Director of Fraunhofer ISE, remarked, “We expect that high-efficiency concentrator technology - in addition to photovoltaics using crystalline silicon and the classic thin-layer technology - will become established as a third technology for cost-efficient generation of solar electricity in the sunny regions of the world.”
Frank Dimroth began doctoral studies at the Fraunhofer ISE in the area of experimental physics and received his Ph.D. in 2000 at the University of Constance. In 2007, he was named manager of the group “III-V Epitaxy and Solar Cells,” which currently has 50 employees. He is the author of around 120 scientific publications and holds nine patents for PV cells and has supervised numerous undergraduate theses and doctoral dissertations in the area of photovoltaics.
In 2005, Dr. Dimroth and Dr. Andreas Bett, Department Head and Deputy Director of Fraunhofer, helped establish Concentrix Solar GmbH, a spin-off of the Institute. The company produces concentrator PV systems and has recently installed its first concentrator solar power plant in Spain.
The “Fondation Louis D” was established 10 years ago by the Institut de France, a non-profit umbrella organization of five French academies including ‘Académie des sciences’. The foundation is dedicated to the advancement of language, science and the arts and presents a major science award each year. The “Fondation Louis D” prize carries a cash value of €750,000.
