A First-Principles Calculation on the Electronic Structures and Optical Properties of Ti/N-Codoped Quartz SiO<SUB>2</SUB>

Abstract

The electronic structures and optical properties of N-doped, Ti-doped and TI/N-codoped SiO2 have been investigated by the means of first-principles calculations. Our results indicate the introduction of doped ions can significantly reduce the band gap compared to the SiO2 system, nearly by 1.4 eV on average, which may be partly attributed to the unoccupied N 2p states and the hybridization of Si 3s, 3p with N 2p and O 2p states. In addition, a strong absorption in the visible light region can be found after doping, while the UV absorption is also improved slightly. So Ti and N atoms may be possible doped elements for improving the optical properties of SiO2 system.