High Growth Rate Rear-Junction GaAs Solar Cell with a Distributed Bragg Reflector

Fast epitaxial growth is an attractive method for reducing III-V photovoltaic device cost. Here, we grow a high-performance, rear-junction GaAs solar cell at 1 µm/min via metal organic chemical vapor deposition. We integrate an epitaxial distributed Bragg reflector with the solar cell to increase the optical path length for photons near the band-edge, enhancing photon recycling without the need for epitaxial lift off. Reflectivity enhancement is evident near the band-edge, permitting up to 96% external quantum efficiency. Device results demonstrate significant performance boost, achieving 1.06 V open-circuit and an efficiency of 24.3% AM1.5G.