含铅空位的PbWO4晶体光学性质及其偏振特性的研究

利用完全势缀加平面波局域密度泛函近似，计算了含铅空位的PbWO₄（PWO）晶 体的电 子结构，模拟计算了复数折射率、介电函数及吸收光谱的偏振特性. 比较含铅空位的PWO晶 体与完整的PWO晶体的吸收光谱及其偏振特性，得到与铅空位相关的吸收光谱及其偏振特性 ，计算结果与实验结果基本相符. 计算得到的含铅空位的PWO晶体的光学偏振特性反映了PWO 晶体的结构对称性. 计算结果表明PWO晶体中350，420，550和680 nm的吸收带的出现与PWO 晶体中铅空位的存在直接相关. 关键词： 4晶体')" href="#">PbWO₄晶体 电子结构 光学性质 铅空位

Optical polarized properties for the PbWO4 crystal containing lead vacancy

The electronic structure, dielectric functions, complex refractive indices and absorption spectra for the polarized light from the perfect PbWO₄(PWO) crystal and the PWO crystal containing V^2-_Pb have been calcula ted using LAPW +LDA method with lattice structure optimized. The peaks of the absorpti on spectra corresponding to the electronic transitions have been studied. The op tical properties of PWO crystal containing V^2-_Pb are aniso trop ic. It may be caused by the anisotropy of lattice structure of the PWO crystal. Our calculated results indicate that the perfect PWO crystal does not have absor ption band in the visible and near_ultraviolet region, but the PWO crystal conta ining V^2-_Pb has absorption bands in visible and near_ultra viol et region. The absorption bands can be well decomposed into four Gaussian_shape bands peaking at about 350, 405, 550 and 670 nm. It predicates that these absor ption bands are related to the existence of the V^2-_Pb in t he PWO crystal.