Abstract
Copper zinc tin sulphur (CZTS) based solar cells (SCs) became a suitable thin film-based photovoltaic device due to their non-toxic constituents and abundance in nature. The high absorption coefficient with a tunable band gap makes it a suitable material for the next-generation-based SCs. CZTS-based SC models demonstrate higher performance. The overall tuning of CZTS-based SCs to improve efficiency is quite difficult. The overall optimization is addressed by considering both the band gap and thickness of the CZTS layer and buffer layers. This study addresses a novel method of using two materials as buffer layers to enhance cell efficiency. The device performance has been improved based on bi-layer buffer materials proposed in this study. The present study uses a SCAPS-1D SC simulator to numerically investigate CZTS/WS2/In2S3-based SC structures, including ZnO as the window layer and CZTS as the absorber layer. The overall optimization has been considered by taking the contour plots among thickness vs. band gap and bandgap vs. band gap. The device's efficiency is recorded as 22.96% when the optimum values of the buffer layer are considered. This work reveals a new idea to fabricate a highly efficient SC based on CZTS material for the next-generation photovoltaic device.