Electronic structure and optical properties of Nb-doped anatase TiO2.

The electronic structure and optical properties of pure and Nb-doped TiO₂ with anatase structure were calculated using local-density approximation based on the density-functional theory. For the undoped TiO₂, the Fermi level locates in the band gap between the conduction band and valence band, while it moves into the conduction band and shows metal-like characteristic after Nb atom was introduced into the TiO₂ supercell. The optical absorption coefficients for both compounds are very small in the visible light range. Our calculations provide electronic structure evidence that the Nb-doped anatase TiO₂ is a new type transparent conducing metal. [ABSTRACT FROM AUTHOR]