MoO 2 Sacrificial Layer for Optimizing Back Contact Interface of Cu 2 ZnSn(S,Se) 4 Solar Cells

The conversion efficiency of Cu2ZnSn(S,Se)4 (CZTSSe) solar cells is relatively low, due to the complicated intrinsic defects and the unsuitable contact interfaces. In this work, MoO2 thin films prepared by a simple preannealing method are introduced to Mo/CZTSSe back contact interface. For the first time, it is found that MoO2 acts as a sacrificial layer rather than the traditional intermediate la...