LiGaX_2(X=S,Se,Te)的电子结构,光学和弹性性质的第一性原理计算  

First-principles calculations of electronic structure,optical and elastic properties of LiGaX_2 (X = S,Se,Te)

作　　者：陈海川[1,2] 杨利君[2] 

机构地区：[1]西华大学电气信息学院,成都610039 [2]四川大学电子信息学院,成都610064

出　　处：《物理学报》2011年第1期268-274,共7页Acta Physica Sinica

摘　　要：采用基于第一性原理的密度泛函理论赝势平面波方法,对LiGaX2(X=S,Se,Te)的能带结构、态密度、光学以及弹性性质进行了理论计算.能带结构计算表明LiGaS2的禁带宽度为4.146eV,LiGaSe2的禁带宽度为3.301eV,LiGaTe2的禁带宽度为2.306eV;其价带主要由Ga-4p层电子和X-np层电子的能态密度决定;同时也对LiGaX2的复介电函数、反射率、折射率和弹性性质进行了理论计算.经比较,计算结果与已有的实验数据符合较好.The density of states,electronic structure,optical and elastic properties of LiGaX2（X = S,Se,Te） are investigated by the first-principles plane-wave pseudopotential density functional theory within the generalized gradient approximation （GGA）. The results show that the band gaps of LiGaX2 （ X = S,Se,Te） are 4. 146 eV,3. 301 eV and 2. 306 eV, respectively. It can be confirmed that the valence bands are mainly composed of X-np or Ga-4p states. The complex dielectric functions,reflectivity,index of refraction and elastic property are precisely calculated by band structure and density of states. The obtained results are in agreement with the available experimental data.

关 键 词：电子结构 光学性质 弹性性质 LGX 

分 类 号：O481[理学—固体物理]