Optimization of ZnO thickness for high efficiency of n-ZnO/p-Si heterojunction solar cells by 2D numerical simulation

In this paper, n-ZnO/p-Si heterojunction was modeled using two-dimensional numerical simulation. The effect of Zinc Oxide thickness on electrical parameters was investigated. This work aimed to study the effect of ZnO thickness on the performances of n-ZnO/p-Si heterojunction solar cell in order to obtain a device with good conversion efficiency. The simulation was carried out by ATLAS Silvaco software. As results, an ideality factor between 1 and 2 was obtained, also the series resistance decreases with increasing ZnO thickness. Furthermore, a short circuit current density of 37.85 mA/cm², an open circuit voltage of 666.28 mV, a fill factor of 81.73% and a photovoltaic conversion efficiency of 20.60% were achieved under AM 1.5 illumination for the optimal ZnO thickness of 250 nm.