First-principles study of oxygen-doped perovskite CsPbX3 (X = Cl, Br, I).

The crystal structure models of O doped CsPbX 3 (X=Cl, Br, I). [Display omitted] • O doped perovskite CsPbX 3 was studied by first principles. • New optical property of CsPbX 3 doped by O are predicted. • O changes the position of the valence band top and conduction band bottom. The electronic structures of perovskite CsPbX 3 (X = Cl, Br, I) and O doped CsPbX 3 have been studied by first principles based on density functional theory (DFT). The theoretical calculation results show that O doping leads to narrow band gap width of perovskite CsPbX 3. For pure CsPbX 3, it is found that the 6p states of Pb determines the position of the conduction band bottom and the p states of halogen determines the position of the valence band top; and for O doped CsPbX 3 , it shows that the incorporation of O is the fundamental reason for the narrowing of band gap and light absorption edge redshifting compared with that of pure CsPbX 3. [ABSTRACT FROM AUTHOR]