Electronic structures and color centers of PbWO4 with lead vacancy
钨酸铅晶体中与铅空位有关的电子结构和色心模型研究

The electronics structures and absorption spectra of polarized light for the PWO crystal containing Vpb^2- have been calculated using CASTEP code with lattice structure optimization. The optimized lattice structures around lead vacancy in the PWO have been obtained. The color center models and their corresponding absorption spectra have been proposed according to the experimental results of the lattice structures and the electronic structures around the lead vacancy. The negative divalent Vpb^2- should trap two holes to maintain the local neutrality. The possible way of the formation of the hole centers is one trapped hole shared by two O^2- ions nearest to Vpb^2- and other one shared by another two O^2- ions nearest to Vpb^2- forming O2^3- - Vpb^2- -O2^3- ]. The different ways of O^2- ions trapping the holes will form different color centers corresponding to different absorption bands. The color center models around Vpb^2- have been proposed.