Improved performance of Cd-free CZTS thin-film solar cells by using CZTS_0.4Se_0.6 BSF layer

Abstract Cu 2 ZnSnS 4 (CZTS) thin film solar cells (TFSCs) have received great attention from the cell industry for their environment, price, high absorption coefficient and electronic properties. This work provides a strategy to prompt photoelectric conversion efficiency (η) of CdS/CZTS-based TFSCs via introducing back surface field (BSF) layer wxAMPS simulate results. Meanwhile, optimum ratio sulfur selenium in BSF material CZTSSe has been also studied, new device structure constructed. Beneficial introduction as layer, interface recombination is suppressed leads an enhanced V oc . Subsequently, MoO 3 , ZnS, WO TiO In S candidates substitute toxic Cd buffer are investigated. The results demonstrate that /CZTSSe exhibits best performance with 28.59 % 0.99 V, ascribed superior spike-like value. It was found presence conduction band (CB) at more suitable offset (CBO) value could suppress interfacial complexation. Therefore, performs material. However, due cost indium, this paper recommends utilization wide bandgap semiconductor materials MoO3 which good stability efficiencies can reach 28.38% 28.41%, respectively. important guidance researchers manufacture CZTS TFSCs.