闪锌矿结构AlSb空位缺陷性质的第一性原理研究

采用基于密度泛函理论(DFT)第一性原理的平面波超软赝势方法,计算含有锑空位和铝空位的电子结构,发现空位引起周围原子弛豫,晶体结构发生畸变。在此基础上研究了空位缺陷对闪锌矿型AlSb体系电子结构的影响,结果表明,铝空位缺陷使锑化铝费米能级降低,带隙变窄;而锑空位缺陷则使锑化铝费米能级升高,带隙变窄,同时,锑化铝的半导体类型由p型变为n型。对光学性质的研究发现,由于空位的引入使其邻近原子电子结构发生变化,使得空位缺陷系统光学性质的变化主要集中在低能量区域。

First-principles Study of Point Defects in Zinc Blende Structure AlSb

The electronic structures of AlSb with vacancy defects were calculated by using density functional theory(DFT) based on the first-principle ultrasoft pseudopotentials method. The results show that the vacancy result in local lattice distortion and the relaxation of neighboring atoms. Then vacancy effects on electronic structure of zinc blende structure AlSb were analyzed. The results reveal that Al vacancy causes Fermi level to a lower energy, narrowing the band gap, while Sb vacancy causes Fermi level to a higher energy, narrowing the band gap and changing the semiconductor type of AlSb from p-type to n-type. The optical properties of AlSb with vacancies were investigated. The results indicate that changes on optical properties mainly focus on low-energy reion because of the electronic structure of atom neighbor vacancy.