Improved performance of graphene/n-GaAs heterojunction solarcells by introducing an electron-blocking/hole-transporting layer

Abstract

Until now, the performance of graphene/GaAs solar cells is not optimized due to interfacial defect states and recombination at the front contact. Using analytical modeling tool: AFORS-HET, we introduce an electron-blocking/hole-transporting layer (EBHTL) in the original structure of graphene/n-GaAs solar cells to improve the overall performance of solar cells. The modified structure performs well in suppressing recombination at the front contact, and is insensitive to the hole and electron recombination rates. Importantly, we obtain a record cell performance with an open-circuit voltage of 833.7 mV, a short-circuit current density of 35.9 mAcm-2 and a photovoltaic conversion efficiency of 20.9%. In addition, for the purpose of selecting the best EBHTL layer, we have also investigated the performance of graphene/EBHL/GaAs solar cells by varying electrical properties of the EBHTL layer.