First principles study on electronic structure and optical property of O-doped lead-free perovskite CsSnCl3

The radii of O2- and Cl- are similar, and O2- can easily replace Cl- into the cell of perovskite CsSnCl3. Herein, the doping model of O-doped lead-free perovskite CsSnCl3 is established. The influence of O doping on the electronic structure and optical properties of CsSnCl3 is studied by first principles calculation based on density functional theory (DFT). The results show that O doping can effectively regulate the band gap of CsSnCl3, and it also indicates that the incorporation of O is the fundamental reason for the change in bandgap and the increase in light absorption coefficient of CsSnCl3.