Recent Advances in Microcell Concentrating Photovoltaics for Space

Microscale concentrating photovoltaics can improve the efficiency and reduce the cost of photovoltaic power in space. We report progress on a lightweight, monolithic, and ultrathin reflective concentrator for space based on triple-junction transfer printed microscale photovoltaic cells. The ~1 mm-thick first-generation prototype validates optical modeling and delivers 24% efficiency with a ± 9° acceptance angle. These results provide the foundation for a second-generation prototype based on an optimal paraboloidal reflector that is predicted to achieve a specific power >350 W/kg over an acceptance angle of ± 7°.