Department of Physics, Nanchang University, Nanchang 330031, China

This work combines the advantages of SnS and CZTSSe to constitute the SnS/CZTSSe heterojunction solar cells, and the effects of various factors on cell performance were studied by using numerical simulation. The results show that the optimal thickness of CZTSSe and SnS are 0.1 μm and 2.0 μm, respectively. Furthermore, the optimal doping concentrations of CZTSSe and SnS are 1×1017 cm-3 and 1×1016 cm-3, respectively. In addition, defect states have little impacts on the cell performance when the density of Gaussian defect states of CZTSSe and SnS are less than 1×1016 cm-3 and 1×1014 cm-3, respectively, and the density of tail defect states of these two materials are both less than 1×1019 cm-3eV- 1. Moreover, the potential conversion efficiency of the SnS/CZTSSe heterojunction solar cells can reach 23.92%. Therefore, the SnS/CZTSSe heterojunction solar cell may be a promising photovoltaic structure.