铁硅化合物β-FeSi_2带间光学跃迁的理论研究  

Interband Optical Transitions in Semiconducting Iron Disilicide β-FeSi_2

作　　者：闫万珺[1] 谢泉[1] 张晋敏[1] 肖清泉[1] 梁艳[1] 曾武贤[1] 

机构地区：[1]贵州大学电子科学与信息技术学院,贵阳550025

出　　处：《Journal of Semiconductors》2007年第9期1381-1387,共7页半导体学报（英文版）

基　　金：国家自然科学基金(批准号:60566001);教育部博士点专项科研基金(批准号:20050657003);教育部留学回国科研基金(批准号:教外司(2005)383);贵州省科技厅国际合作项目(批准号:黔科合G(2005)400102);贵州省教育厅重点基金(批准号:05JJ002);贵州省留学人员科技项目(批准号:黔人项目(2004)03);贵州省委组织部高层人才科研资助项目~~

摘　　要：采用基于第一性原理的赝势平面波方法系统地计算了β-FeSi2基态的几何结构、能带结构和光学性质.能带结构计算表明β-FeSi2属于一种准直接带隙半导体,禁带宽度为0.74eV;其能态密度主要由Fe的3d层电子和Si的3p层电子的能态密度决定;利用计算的能带结构和态密度分析了带间跃迁占主导地位的β-FeSi2材料的介电函数、反射谱、折射率以及消光系数等光学性质计算结果,复介电函数的计算结果表明β-FeSi2具有各向异性的性质;吸收系数最大峰值为2.67×105cm-1.The geometric parameters and the electric and optical properties of β-FeSi2 are calculated using first principle methods based on plane-wave pseudo-potential theory in detail. The results indicate that： （1） β-FeSi2 is a quasi-direct semiconductor and the band gap is 0.74eV. The density of states is mainly composed of Fe 3d and Si 3p. （2） The valences electronic state of β-FeSi2 is asymmetric and has a strong local area characteristic. These have an important influence on the electronic structure and the bonding characteristics of β-FeSi2. （3） The calculation of the dielectric function reveals that β-FeSi2 is anisotropic,the biggest peak of absorption is 2.67 × 10^5 cm^-1, the extinction coefficient shows strong absorption characteristic near the band edge,and the mechanism of the electric and optical properties of β-FeSi2 dominated by electron inter-band transitions are analyzed in terms of calculated band structure and density of states.

关 键 词：Β-FESI2 电子结构 光学特性 

分 类 号：TN301[电子电信—物理电子学]