First-Principles Studies on the Electronic Structures andOptical Properties for the PbWO4 Crystal Containing VPb2−

Abstract

The electronic structures, dielectric functions,complex refractive indices and absorption spectra for a perfectPbWO4 (PWO) crystal and the PWO crystals containing lead vacancyVPb2− have been calculated using a full-potential(linearized) augmented plane-wave (LAPW) + local orbitals (LO) methodwith the lattice structure optimized. The peaks of the absorptionspectra corresponding to the electronic transitions have been studied.The calculated results indicate that the absorption band of the perfect PWOcrystal does not occur in the visible region. However, the PWO crystalcontaining VPb2− has two additional absorption bands inthis region. The two bands can be well decomposed into fourgaussian-shape bands peaking at 350 nm, 405 nm, 550 nm and 670 nm,respectively, which coincide well with the 350 nm, 420 nm, 550 nm and680 nm absorption bands measured in PWO crystals. Therefore, it can beconcluded that the 350 nm, 420 nm, 550 nm and 680 nm absorption bands arerelated to the existence of VPb2− in the PWO crystal.