Surface lattice engineering through three-dimensional lead iodide perovskitoid for high-performance perovskite solar cells

Surface modification of organic-inorganic halide perovskite thin films represents a promising approach to enhance the efficiency and stability of perovskite solar cells. Here, we synthesized N-methyl-1,3-propane diammonium diiodide (Me-PDAI(2)) and found that Me-PDA(2+) can template a three-dimensional perovskitoid'' structure (Me-PDA)Pb2I6. Simple surface treatment with Me-PDAI(2) on top of a standard(FAPbI(3))(0.85)(MAPbI(2)Br)(0.10)(CsPbI3)(0.05) perovskite induces the formation of a thin (Me-PDA)Pb2I6 perovskitoid surface layer, leading to smoother surface texture, longer charge-carrier lifetime, higher charge-carrier mobility, and a reduced surface-defect density. With the perovskitoid surface modification, the device efficiency is significantly improved from 20.3% to 22.0% along with enhanced stability in both shelf life (ISOS-D-1 stability) and operation (ISOS-L-1 stability). We further demonstrated that the perovskitoid surface engineering approach is applicable to various perovskite compositions, including CsFAMA-, FAMA-, and MA-based lead halide perovskites, making perovskitoid an important design motif for perovskite surface engineering for enhanced device performance and stability.

Automated summary

Surface modification with a new compound, Me-PDAI(2), on standard perovskite thin films can induce the formation of a thin perovskitoid surface layer, leading to improved efficiency and stability of the solar cells.