CrSi2能带结构和光学性质的第一性原理研究

First-principles study on the electronic structure and optical properties of CrSi2

采用基于第一性原理的密度泛函理论（DFT）赝势平面波方法，对CrSi2的能带结构、态密度和光学性质进行了理论计算，能带结构计算表明CrSi2属于一种间接带隙半导体，禁带宽度为0．353eV,其能态密度主要由Cr的3d层电子和Si的3p层电子的能态密度决定；计算了CrSi2的介电函数、反射率、折射率及吸收系数等。经比较，计算结果与已有的实验数据符合较好。

By using the first principle methods based on plane-wave pseudo-potential theory, geometric parameters, electronic structure and optical properties of CrSi2 were studied. The calculation of band structure show that CrSi2 is an indirect semiconductor and the band gap is 0.35eV. Density of state is mainly composed of Cr 3d and Si 3p. The calculation of dielectric functions show that the anisotropy of the optical properties of CrSi2 is not large. Moremove, the reflectivity, absorption coefficient and refractive index were calculated from the obtained dielectric functions. The calculated results of optical properties are in argreement with the experiments.