Structural, Electronic and Optical Properties of S-Doped Anatase TiO<sub>2</sub><sub></sub>

Structural, electronic and optical properties of S-doped anatase TiO 2 have been investigated using the first-principles density-functional theory. The band structure and density of states show that the band gap of anatase TiO 2 narrows due to the presence of the S-3p energy level in the top of the valence bands. Compared with the optical absorption edge of the undoped anatase TiO 2 , the optical absorption edge of S-doped anatase TiO 2 shifts to a lower energy, which indicates that S-doped anatase TiO 2 can be used for visible-light absorption applications.