Electronic structure and optical properties of V- and Nb-doped ZnO from hybrid functional calculations

Highlights: • A systematical investigation has been performed for Nb and V-doped ZnO system. • Hybrid functional results are in good agreement with experimental values. • Both V and Nb doping shows strong absorptions in visible light region. • The V doping has a critical point for optical absorption while Nb doping does not. • Both V and Nb doping shows significant optical anisotropy. - Abstract: The electronic structure and optical properties of multiple donors V and Nb doped ZnO were systematically investigated using the hybrid functional calculations. The localized states form near the Fermi level and decrease with the doping concentration of V, while Nb doping gives an opposite trend. Significant visible light absorptions were obtained from both V and Nb doping, while the variation trend of optical properties with the doping concentration shows obvious difference. Additionally, V doped ZnO prefers to absorb the polarized light along (0 0 1) direction, while Nb doping enhance the absorption along (1 0 0) direction. These results provide useful predictions to design doping strategy for ZnO materials in photoelectric and photocatalytic applications