Ce掺杂CrSi2电子结构和光学性质的第一性原理研究

采用基于密度泛函理论的第一性原理计算方法，对未掺杂及Ce掺杂CrSi2的电子结构和光学性质进行理论计算。计算结果表明，未掺杂CrSi2是间接带隙半导体，其禁带宽度为0.392 eV，掺杂Ce元素，仍然是间接半导体，带隙宽度下降为0.031eV。未掺杂CrSi2在费米能级附近主要由Cr-5d、Si-3p态贡献。Ce掺杂后在费米能级附近主要由Cr-5d轨道，Ce-4f轨道，C-2p，Si-3p轨道贡献，掺杂后电导率提高。未掺杂CrSi2有两个介电峰，掺杂后，只有一个介电峰。未掺杂CrSi2，在能量为6.008处吸收系数达到最大值，掺杂后在能量为5.009eV处，吸收系数达到最大值。

First principles study of electronic structures and optical properties of Ce-doped 6H-SiC

The electronic structures and optical properties of undoped and Ce doped CrSi2 were calculated by the first principle calculation method based on density functional theory. Undoped CrSi2 is an indirect bandgap semiconductor, whose gap width is 0.392 eV and Ce doped CrSi2 is also an indirect bandgap semiconductor,whose gap is reduced to 0.031eV.The Rermi level of undroped CrSi2 is contributed by the electronic orbit of Cr-5d,Si-3p. The Rermi level of Ce droped is mainly contributed by the 5d electronic orbit of Cr-5d and the Ce-4f , C-2p,Si-3p.Two dielectric peak appears at the undroped CrSi2.One dielectric peak appears at the Ce-droped CrSi2.The maximum of absorption coefficient of un-droped CrSi2 is the photon energy of 6.008eVand the maximum of absorption coefficient of Ce- droped CrSi2 is the photo energy of 5.009eV.