钨酸铅晶体中与氧空位相关的色心研究

Theoretical study on defects associated with oxygen vacancy in PbWO_4 crystal

采用基于相对论性密度泛函理论的离散变分和嵌入团簇方法计算了PbWO4 晶体中与氧空位VO 及其相关色心的态密度分布 ,并运用过渡态方法计算了其激发能 .结果表明 :VO 的存在可以使WO42 - 基团的禁带宽度明显变小 ;PbWO4 晶体中VO 可以产生F+ ,并且F+ 的存在可以使晶体引起 4 2 0nm的吸收 ,另外PbWO4 晶体中VO 可能不会产生F心 .

In this study, the defect associated with oxygen vacancy V-o in lead tungstate crystals( PbWO4), was investigated by the relativistic self-consistent discrete variational embedded cluster method. We focused on the density state and the effect of color centre induced by V-o on the surroundings. The results showed that, V-o could produce the WO3 + F+ defect in the crystal, and the existence of F+ could result in the absorption of 420nm. In addition, there was not V centre in the PbWO4 crystal.