Study on the electronic structures and absorption spectra for the PbWO4 crystal with the defect [V2+O-V2-Pb-V2+O]2+

The electronic structures and absorption spectra for the perfect PbWO4 (PWO) crystal and the crystal containing aggregated defect [V2+O-V2-Pb-V2+O]2+ have been calculated using density functional theory code CASTEP with the lattice structure optimized. The calculated absorption spectra of the PWO crystal containing the aggregated defect [V2+O-V2-Pb-V2+O]2+ exhibit three absorption bands peaking at 1.68 eV (740 nm), 2.25 eV (560 nm), 2.50 eV (470 nm). It predicts that the 450-750 nm absorption bands are related to the existence of the aggregated defect [V2+O-V2-Pb-V2+O]2+ in the PWO crystal