First Principle Studies on the Optical Properties of PbWO_4 Crystal With Oxygen Vacancy V_o~(2+)

摘要

The electronic structures, dielectric function, complex refractive indices and absorption spectra of the perfect PbWO_4 crystal and the crystal containing oxygen vacancy V_o~(2+) have been calculated using full-potential (linearized) augmented plane-wave (LAPW) + local orbitals (lo) method with the lattice structure optimized. The results indicate that the perfect PWO crystal does not occur absorption band in the visible and near-ultraviolet region. However, the calculated absorption spectrum of the PWO crystal containing V_o~(2+) has two bands peaking at 370nm and 420nm in the visible and near-ultraviolet region respectively. It reveals that the 350nm and 420nm absorption bands are related to the existence of V_o~(2+) in the PWO crystal.