Theoretical study on defect properties of two-dimensional multilayer Ruddlesden-Popper lead iodine perovskite

The defect properties of multilayer two-dimentional (2D) Ruddlesden-Popper Lead Iodine perovskite including the transition energy levels, the formation energy, and the self-compensation of defects have been investigated by utilizing the density functional theory (DFT). The achieved results indicate that the transition energy levels of certain dominant defects (Ii and VI) on the surface are deeper than those of the same type of defects inside of multilayer 2D perovskite, which may reduce the carrier concentration resulting in the decrease of charge mobility. This research provides a very meaningful reference for understanding the properties of 2D perovskite and thus improving its device performance.