【摘要】 为了研究红外透光闪锌矿ZnSe晶体光学性质和电学性质的内在机理。通过第一性原理的密度泛函理论,借助超软平面波赝势,计算了ZnSe晶体的能带结构和态密度,分析了反射光谱、吸收光谱和介电常数。基于有效质量的近似理论,计算了价带顶端附近电子的有效质量。研究结果表明:ZnSe晶体属于直接带隙半导体材料,反射峰的出现主要是因为Se原子的4p电子和Zn原子的3d态电子向导带跃迁,介电峰的分布与电子结构直接相关,介电峰主要是由于Zn的3d和Se的4p轨道价带向Zn的4s和Se的4s轨道导带的过渡。分析了价带顶端的电子有效质量,计算结果与文献资料基本一致,发现载流子的有效质量具有各向异性,k_a方向的电子和空穴的有效质量均较小。从而挖掘了ZnSe晶体的光电性质与有效质量的内在本质,这些分析结果对Ⅱ-Ⅵ族半导体光电子材料具有非常重要的参考价值。更多还原

【Abstract】 The paper aims to study the internal mechanism of optical properties and electronic properties of zinc-blende ZnSe.In the framework of the density functional theory based on first principal theory,the plane wave ultra-soft pseudo-potential technology was employed to calculate the band structure,the density of states of ZnSe crystal.Its reflectivity spectroscopy,absorption spectroscopy and dielectric function were analyzed.Based on the approximation theory of the effective mass,the effective mass of the electron around the top of valence band was calculated.The results show that ZnSe crystal is a kind of direct band-gap semiconductor material.The reflection peaks are caused by the transition of 4 p electrons of Se atom and 3 D state of Zn atoms to the conduction band.The distribution of dielectric peaks is directly related to the electronic structure.The dielectric peak is mainly due to the transition of 4 p orbital valence bands of Zn and Se to 4 s of Zn and 4 s of Se.The effective mass of electrons at the top of the valence band is analyzed.The calculated results are in good agreement with the literature.It is found that the effective mass of the carriers is anisotropic.The electrons and holes along k_a direction have smaller effective mass.Thus,the intrinsic nature of the optoelectronic properties and the effective mass of ZnSe crystal is revealed.Those results may have significant reference in studying Ⅱ-Ⅵ group semiconductor optoelectronic materials.更多还原