First-principles calculations of electronic structure and optical properties of strained Mg_2Si  

作　　者：CHEN Qian XIE Quan ZHAO FengJuan CUI DongMeng LI XuZhen 

机构地区：[1]Institute of New Optoelectronic Materials and Technology, College of Science, Guizhou University, Guiyang 550025, China

出　　处：《Chinese Science Bulletin》2010年第21期2236-2242,共7页

基　　金：supported by the National Natural Science Foundation of China(60566001,60766002);the Major International Joint Research Program from the Ministry of Science and Technology of China (2008DFA52210);the Project of Guizhou Province Information Industry Department(0831);the Undergraduate Carve Out Project of Bureau of Guiyang Science and Technology(6-5)

摘　　要：A detailed theoretical study on structural,electronic and optical properties of Mg2Si under the isotropic lattice deformation was performed based on the first-principles pseudopotential method.The results show that the isotropic lattice deformation results in a linear decrease in the energy gap for the directΓ15-Γ1 and indirectΓ15-L1 transitions from 93%to 113%,while the indirect band gapΓ15-X1 increases from 93%to 104%and then reduces over 104%.When the crystal lattice is 93%compressed and 113% stretched,the magnesium silicide is a zero-gap semiconductor.Furthermore,the isotropic lattice deformation makes the dielectric function shift and the static dielectric constant change.A detailed theoretical study on structural, electronic and optical properties of Mg2Si under the isotropic lattice deformation was performed based on the first-principles pseudopotential method. The results show that the isotropic lattice deformation results in a linear decrease in the energy gap for the direct Г15-Г1 and indirect Г15-L1 transitions from 93% to 113%, while the indirect band gap Г15-X1 increases from 93% to 104% and then reduces over 104%. When the crystal lattice is 93% compressed and 113% stretched, the magnesium silicide is a zero-gap semiconductor. Furthermore, the isotropic lattice deformation makes the dielectric function shift and the static dielectric constant change.

关 键 词：第一原理赝势法 MG2SI 电子结构 光学性质 晶格变形 计算 各向同性 静态介电常数 

分 类 号：O614.22[理学—无机化学]