Efficient and Stable Perovskite Solar Cells via CsPF6 Passivation of Perovskite Film Defects

Polycrystalline perovskite films have many fatal defects; defect passivationcan improve the performance of perovskite solar cells (PSCs). In this study, the defects inperovskitefilms are passivated by introducing the pseudohalide salt CsPF6into thefilms.Because the ionic radii of Cs+and PF6-are close to those of FA+and I-, respectively, theycan be uniformly doped into perovskitefilms to passivate the bulk, surface, and grainboundary defects. The photovoltaic performance of the PSCs significantly improved afterpassivation. Moreover, the photoelectric conversion efficiency increased significantly from21.36% to 23.15% after passivation. Because of defect passivation, PSCs also exhibit goodenvironmental stability. This study introduces a scheme for improving the photovoltaic performance of PSCs via passivation