Efficient and Stable Perovskite Solar Cells via CsPF 6 Passivation of Perovskite Film Defects.

Polycrystalline perovskite films have many fatal defects; defect passivation can improve the performance of perovskite solar cells (PSCs). In this study, the defects in perovskite films are passivated by introducing the pseudohalide salt CsPF 6 into the films. Because the ionic radii of Cs + and PF 6 - are close to those of FA + and I - , respectively, they can be uniformly doped into perovskite films to passivate the bulk, surface, and grain boundary defects. The photovoltaic performance of the PSCs significantly improved after passivation. Moreover, the photoelectric conversion efficiency increased significantly from 21.36% to 23.15% after passivation. Because of defect passivation, PSCs also exhibit good environmental stability. This study introduces a scheme for improving the photovoltaic performance of PSCs via passivation.