Prospects of Zn(O,S) as an alternative buffer layer for Cu 2 ZnSnS 4 thin‐film solar cells from numerical simulation

Zn(O,S) is an attractive alternative to CdS as a buffer layer of Cu 2 ZnSnS 4 (CZTS)‐based solar cell due to its higher bandgap and environmental friendliness. In this work, CZTS solar cell with a structure of CZTS/Zn(O,S)/Al:ZnO was simulated by Solar Cell Capacitance Simulator (SCAPS). The impacts of thickness and acceptor concentration of CZTS, thickness and donor concentration of Zn(O,S) and operating temperature on the performance of CZTS solar cells were investigated. It has been obtained that the optimum thickness of CZTS is between 2000 and 3000 nm and that of Zn(O,S) is about 50 nm. The suitable doping concentrations of CZTS and Zn(O,S) layers are around 10 16 and 10 17 cm −3 , respectively. The temperature coefficient of efficiency is about −0.023 %/K in the CZTS solar cell. All these simulation results will provide some important guidelines for fabricating high efficient CZTS solar cells.