Origins and Suppression of Sn(Ⅱ)/Sn(Ⅳ) Oxidation in Tin Halide Perovskite Solar Cells

摘要

Tin halide perovskite solar cells (TPSCs) have attracted aggressive researchinterest in the emerging perovskite photovoltaic devices due to theireco-friendliness as compared to their lead halide counterparts. However, theeasy Sn(Ⅱ)/Sn(Ⅳ) oxidation of tin perovskites is a serious impediment to thedevelopment of TPSCs. Therefore, a clear understanding of the mechanisms,origins, and effects of the oxidation is essential to further boost theperformance and stability of TPSCs. Herein, a systematic overview of thephysicochemical process for the Sn(Ⅱ)/Sn(Ⅳ) oxidation in TPSCs from thestarting precursors to the final devices is presented. In addition, the effects ofoxidation on the performance of TPSCs are then reviewed from crystalstructure, defect chemistry, and optoelectronic properties. More importantly,the key issues to suppress the Sn(Ⅱ)/Sn(Ⅳ) oxidation are seriously discussedon the basis of the reported antioxidation strategies. Finally, the challengesand outlooks toward TPSCs with higher power conversion efficiency andstability are proposed.