Potassium Acetate Passivated SnO2 Interface for High‐Efficiency Two‐Step Deposited Perovskite Solar Cells

Abstract The quality of the tin dioxide interface has an important impact on the performance of perovskite solar cells. Herein, a facile potassium acetate strategy to effectively treat the SnO 2 /perovskite interface and enhance the film quality of perovskite crystals is used. The defect density at the interface can be reduced, thereby suppressing the nonradiative recombination of excitons. Enhanced performance of the two‐step deposited perovskite device is obtained with an open‐circuit voltage ( V OC ) of 1.173 V, a fill factor of 78.31%, and a power conversion efficiency of 23.63%.