CdS_xSe_(1-x)合金结构、电子结构和光学性质的第一性原理研究

First- principles calculations of structural,electronic and optical properties of CdS_xSe_(1-x) alloys

用密度泛函理论究了闪锌矿型三元合金体系Cd SxSe1-x的晶体结构、电子结构和光学性质.计算了组分参数在0≤x≤1范围内Cd SxSe1-x的电子结构、态密度和带隙,计算结果表明Cd SxSe1-x为直接带隙半导体材料,其带隙随Se含量的增加而减小.分析了Cd SxSe1-x的复介电函数和吸收系数等光学性质随光子能量变化的关系,随Se元素含量增加,各光学特性曲线向低能方向移动.

The electronic structure,electronic and optical properties of Cd SxSe1- xalloys were studied using the first- principles calculations based on the density functional theory（ DFT）. Electronic structure,density of states and energy bandgap for Cd SxSe1- xwere estimated in the range 0 ≤ x ≤1. It is observed that the direct bandgap Egof Cd SxSe1- xdecreases with the increase of Se content. Furthermore,results for complex dielectric constants and absorption coefficients were also described. All optical characteristic curves of Cd SxSe1- xslightly shift to low energy with the increase of Se content.