Perovskite Solar Cells Based on Compact, Smooth FA0.1MA0.9PbI3 Film with Efficiency Exceeding 22%

The utilization of mixed cations is beneficial for taking the advantages of cations and achieving highly efficient perovskite solar cells (PSCs). Herein, the precisely small incorporation of CH(NH2)(2) (FA) cations in methyl ammonium lead iodide (MAPbI(3)) enables the formation of compact, smooth perovskite film with high crystallinity. Consequently, the short-circuit current and the fill factor of the PSCs based on FA(x)MA(1-x)PbI(3) perovskite are greatly improved, leading to the enhanced device efficiency. The champion PSC based on FA(0.1)MA(0.9)PbI(3) exhibits a remarkably high efficiency of 22.02%. Furthermore, the PSCs based on FA(0.1)MA(0.9)PbI(3) perovskite also show improved device stability. This work provides a simple approach to fabricate high-quality perovskite films and high-performance PSCs with better stability.