Theoretical study of optical and ultraviolet photoemission spectra of TiO 2 and VO 2 in rutile phase

Abstract

The optical spectra for two light polarizations and the ultraviolet photoemission spectra (UPS) of TiO 2 and VO 2 in rutile phase have been calculated ab initio on the bbase of the self-consistent energy band structure. The semirelativistic extended linear augmented plane wave method (ELAPW) was employed. In the case of TiO 2 the structures in the theoretical reflectivity curves are shifted by 1–1.5 eV to lower energies with respect to their measured positions, which is attributed to strong quasiparticle effects in this material. The reflectivity spectra of the metallic VO 2 are in a good agreement with experiment. The photoelectron energy distribution curves (EDC's) agree well with experiment for both semiconducting TiO 2 and metallic VO 2 .