Schottky Defects Suppress Nonradiative Recombination in CH₃NH₃PbI₃ through Charge Localization

Hybrid lead halide perovskites are promising materials for photovoltaic applications due to their exceptional optoelectronic properties. Here, we investigate the impact of Schottky defects─specifically PbI₂(V_PbI₂) and CH₃NH₃I (V_MAI) vacancies─on nonradiative recombination in CH₃NH₃PbI₃ using time-dependent density functional theory and nonadiabatic (NA) molecular dynamics. Our results reveal that Schottky defects do not alter the fundamental bandgap or introduce trap states but instead distort the surrounding lattice, localizing the hole distribution. This reduces the spatial overlap of electron and hole wave functions, weakening NA coupling and increasing intensitieis of high-intensity phonon modes that accelerate dephasing. Consequently, nonradiative recombination lifetimes extend to 2.1 and 2.6 ns for V_PbI₂ and V_MAI, respectively─over double that of pristine CH₃NH₃PbI₃. This work demonstrates the potential of Schottky defects to enhance perovskite solar cell performance by suppressing nonradiative recombination.