First-principles study on electronic structure and optical properties of different concentrations of Bi-doped TiO2

The optical properties of TiO 2 are changed while doped with impurity atoms. This paper made a systematical calculation of the bandgap, the density-of-states (DOS), the optical properties for pure TiO 2 , and Bi-doped anatase TiO 2 according to the first-principles plane wave ultrasoft pseudopotential method which is primarily based on the density functional theory (DFT). The calculation results exhibit that the bandgap decreased after doping, and the impurity energy level is produced into the bandgap of Bi-doped TiO 2 , which makes red-shift for the absorption band edge of Bi-doped TiO 2 and the absorption is enhanced more in the visible light range.