Efficiency improvement for InGaN/GaN multiple-quantum-well solar cells with vertical configuration

Abstract

We demonstrated InGaN/GaN multiple-quantum-well solar cells with enhanced photovoltaic characteristics using vertical configuration. As compared to the conventional solar cell device, the vertical device with a bottom Al reflector and a top textured surface exhibits much improved performances, including a short-circuit current density of 1.2 mA/cm2, an open-circuit voltage of 1.9 V, a fill factor of 57.6 % and a conversion efficiency of 1.3 %. The bottom Al reflector could reflect a large amount of photons back into the absorption layer, which led to the improvement of light absorption. In addition, due to the top surface texturing, reflection is reduced that further improved the absorption. The combination of a bottom Al reflector and a top textured surface, which yields much higher conversion efficiency than a conventional device, shows great promise for future photovoltaic applications.