30.06.2021 Record Efficiency of 68.9% for GaAs Thin Film Photovoltaic Cell Under Laser Light In addition to the classical applications for solar cells on roofs and open spaces, photovoltaic devices can also be used with laser light for efficient power transmission. At the 48th IEEE Photovoltaic Specialists Conference, researchers from the Fraunhofer Institute for Solar Energy Systems ISE recently presented how they were able to achieve a record conversion efficiency of 68.9% with a photovoltaic cell under monochromatic laser light. For this, the research team used a very thin photovoltaic cell made of gallium arsenide and applied a highly reflective, conductive mirror on the backside.