Soitec, CEA-Leti of France and the Fraunhofer Institute for Solar Energy Systems ISE in Germany, have developed a multi-junction solar cell that converts a world record 46 percent of solar light into electricity. The Japanese AIST (National Institute of Advanced Industrial Science and Technology) a center for independent verification of solar cell performance, confirmed the record efficiency at a solar concentration of 508 suns.
Concentrator photovoltaic systems employ small III-V compound semiconductor -based multi-junction cells and a Fresnel lens to concentrate the sunlight to produce low-cost electricity. The cooperative also reported the previous world record in September 2013. The world record cell is a four-junction cell in which each sub-cells converts exactly one quarter of the incoming photons in the wavelength range between 300 and 1750 nm into electricity. The cooperative precisely tuned the composition and thickness of each layer of the cell structure to distribute the photons evenly among each of the four subcells.
Jocelyne Wasselin, vice president solar cell product development for Soitec of France, stated, “We are very proud of this new world record. It confirms we made the right technology choice when we decided to develop this four-junction solar cell and clearly indicates that we can demonstrate 50% efficiency in the near future.” She added, “To produce this new generation of solar cells, we have already installed a line in France. It uses our bonding and layer-transfer technologies and already employs more than 25 engineers and technicians.”