Electronic Properties of F, Cl and H Atoms Adsorbed on CsPbI3(110) Surface

Abstract

The electronic properties of the CsPbI3 surface are calculated by using first-principles calculations. Through calculating adsorption energy of CsPbI3 passivated by Cl, F and H atoms, it is found that adsorption energy values of CsPbI3 (110) surface passivated by H atoms fluctuate less, they are less sensitive to the adsorption position, and the adsorption is stable. Through calculating surface states of passivation system, it is found that F and H atoms have quite good passivation effect, and the Fermi level of passivation system increases and enters the forbidden band, indicating that the passivation effect is relatively ideal. Passivation effect of Cl atoms are poor, a new shallow acceptor defect states appeared at the bottom of the conduction band. This defect level could trap carriers and weaken the carrier migration ability, which is a disadvantage of Cl passivation system. Through the charge density difference and Bader charges, it is found that the F and H atoms get more electrons from the I atom, which is beneficial to the passivation of the surface states.