First-principles study of electronic structures and optical properties of Cu, Ag, and Au-doped anatase TiO2

摘要

We perform first-principles calculations to investigate the band structure,density of states, optical absorption, and the imaginary part of dielectricfunction of Cu, Ag, and Au-doped anatase TiO2 in 72 atoms systems. Theelectronic structure results show that the Cu incorporation can lead to theenhancement of d states near the uppermost of valence band, while the Ag and Audoping cause some new electronic states in band gap of TiO2. Meanwhile, it isfound that the visible optical absorptions of Cu, Ag, and Au-doped TiO2, areobserved by analyzing the results of optical properties,.which locate in theregion of 400-1000 nm. The absorption band edges of Cu, Ag, and Au-doped TiO2shift to the long wavelength region compared with the pure TiO2. Furthermore,according to the calculated results, we propose the optical transitionmechanisms of Cu, Ag, and Au-doped TiO2, respectively. Our results show thatthe visible light response of TiO2 can be modulated by substitutional doping ofCu, Ag, and Au.