压力效应对CdS电子结构和光学性质的影响

Influence of Pressure Effect on CdS Electronic Structure and Optical Properties

基于密度泛函理论体系下的广义梯度近似(GGA)方法,利用第一性原理计算了不同压强下CdS晶体闪锌矿结构,得到其晶格常数、总能量、电子态密度分布、能带结构、光反射与吸收系数等性质,通过比较能带结构的变化行为,得出CdS在116.8 GPa附近还存在等结构相变,即由直接带隙结构变为间接带隙结构。结合电子结构系统分析了压力效应对CdS的光学性质的影响。

The lattice constant, the total energy, density of state, energy band structure, optical reflection and absorption properties of the zinc blende structure CdS under different pressure are calculated by using the generated gradient approximation （GGA） method based on density functional theory. Comparison of the electronic properties of CdS at high pressure with the energy band structural information indicates that a non-structural transition occurs at about 116.8 GPa, in which the direct band structure transforms to an indirect band structure. According to the electronic structure, the optical properties are analyzed systemically under different pressure.