A DFT+U Study of the Structural and Electronic Properties of Zinc Doped Anatase TiO2 Nanomaterial

Abstract

This work reports a theoretical study on the structural and electronic properties of the anatase phase of titanium dioxide (TiO2) within the framework of density functional theory corrected for on-site coulomb interactions in strongly correlated materials (DFT+U). The exchange correlation was described by local density approximation (LDA). The optimized lattice parameters obtained for the pure anatase TiO2 agree with the experimental data. Our results revealed that, after the zinc doping, the structure didn't change but there was a little expansion in the volume of the pure material. It was found that the doped structure's stability increases as the concentration of the dopant increases, but all the doped structures are stable. However, introducing the zinc dopant has significantly reduced the band gap of the pure anatase by 80.7 %, 80 %, and 78.6 % due to 0.25, 0.5, and 0.75 doping concentrations, respectively. This implies that the band gap energy increases as the doping concentration increases.