Theoretical Study of Using Kinetics Strategy to Enhance the Stability of Tin Perovskite
Qi Wei, Youqi Ke, Zhijun Ning
Abstract
Tin perovskite solar cell received great attention in recent years owing to its optimum bandgap and heavy metal‐free property. The main concern for the development of tin perovskite is the oxidation from Sn 2+ to Sn 4+ . Herein, we report a surface hetero‐protection strategy to avoid the surface reaction of tin perovskite. Three types of materials, including low‐dimensional tin perovskite, alkali metal halide, and oxides of group IVA element, are exploited as protecting materials on tin perovskite surface with first‐principles calculation. The lattice mismatch, oxidation resistance, and interface stability of these materials are investigated to search for ideal protecting‐layer materials. After screening over 30 candidates, we finally obtain 8 suitable materials (SiO 2 , GeO 2 , KCl, NaBr, CsF, LiF, LiI, CsSn 2 Br 5 ) for hetero‐protection of tin perovskite. To further understand their application potential in a solar cell device, we then calculate the property of charge transfer between the interface of these materials and tin perovskite. Our study provides a guide for the experimental realization of efficient and stable tin perovskite solar cell.