Si空位缺陷对Ca2Si电子结构及光学性质的影响研究

Vacancy Defect of Si Effects on Electronic Structure and Optical Properties of Ca2Si

基于第一性原理的方法计算了含Si空位缺陷Ca2Si的几何结构、能带结构、电子态密度及光学性质。计算结果表明,Si空位缺陷出现使Ca2Si的晶胞体积增大,带隙变宽,导电类型为n型,静态介电常数、反射率增大,介电函数虚部ε2、吸收系数向低能方向移动。

The geometry structure,band structure,density of states and optical properties in Ca2Si containing Si vacancy defects were calculated by the first-principles method.The calculation results show that the Si vacancy defect increases the volume of Ca2Si,widens the band gap,and the conductivity type is n-type.The static dielectric constant and reflectivity are increased,andε2 and absorption coefficient are moved toward the low energy direction.