Passivation of PEA+ to CsPbI3 (110) Surface States: From the First Principles Calculations

This work investigates the effect of passivation on the electronic properties of inorganic perovskite CsPbI3 materials by using first-principles calculations with density functional theory (DFT). The passivation effect after the addition of Phenylethylamine (PEA+ ) molecule to CsPbI3 (110) surface is studied. The results of density of states (DOS) calculations show that the CsPbI3 (110) surface model with I atom terminated reveals new electronic DOS peaks (surface states) near the Fermi level. These surface states are mainly due to the contribution of I-5p orbital and are harmful to the CsPbI3-based solar cells because they reduce the photoelectric conversion efficiency. The surface states near the Fermi level are significantly reduced, and the decline rate reaches 38.8% with the addition with PEA+ molecule to the CsPbI3 (110) surface.