Achieving high photovoltaic performance in graphene/AlGaAs/GaAs Schottky junction solar cells by incorporating an InAlGaP hole reflector layer

Abstract

The purpose of this study is to enhance the efficiency of Graphene/AlGaAs/GaAs Schottky junction solar cells by introducing various Ga-based thin-film materials as a hole reflector (HR) layer. These HR layers are designed to minimize the recombination rate at the back contact and increase the photogeneration rate. In order to investigate the effect of various HR layers on the efficiency of GaAs solar cells, a reference cell was simulated with an efficiency of 14%. The simulation was conducted using the Silvaco ATLAS simulator, under AM1.5G light with a power density of 100 mW/cm2. Subsequently, InAlGaP (InAl0.65Ga0.35P), AlGaAs (Al0.2Ga0.8As), and InGaP (In0.5Ga0.5P) thin films were individually introduced as HR layers to the Graphene/AlGaAs/GaAs single junction solar cell (SJSC). The addition of HR layers to the conventional Graphene/AlGaAs/GaAs Schottky junction solar cell was found to improve the short-circuit current density (Jsc) by enhancing carrier collection and reducing back interface recombination. This approach has also led to a significant increase in external quantum efficiency (EQE) at long wavelengths of around 500–900 nm. The results of this study demonstrate that incorporating an InAlGaP HR layer in the proposed structure due to its wide bandgap, higher photogeneration rate, and higher absorption rate significantly improves the EQE by absorbing longer wavelength photons and increases the efficiency of the solar cell by more than 1.6%.