Defect Passivation of CsPbBr3 with AgBr for High‐Performance All‐Inorganic Perovskite Solar Cells

CsPbBr3-based perovskite solar cells possess both high humidity and temperature tolerance, and also have excellent long-term stability in air, but the defect states in the bulk perovskite are always an obstacle for further improvement of their efficiency. Herein, a doping strategy is demonstrated in which AgBr is directly added to the precursor solution in the first step. An appropriate amount of Ag+ ion doping can passivate the defects in bulk or at grain boundaries, reduce the defect density of the film, and form a pinhole-free film. Finally, the best power conversion efficiency of the solar cell reaches to 6.92% and exhibits a long-term stability in a humid environment. This work provides a simple and effective method for improving the quality of CsPbBr3 film and the performance of CsPbBr3-based perovskite solar cells.