摘要
采用基于密度泛函理论的第一性原理赝势平面波方法系统计算了Mg2Si及掺Ag、Al的能带结构、态密度和光学性质。计算结果表明,未掺杂Mg2Si属于间接带隙半导体,禁带宽度为0.2994 eV,其价带主要由Si的3p及Mg的3s、3p态电子构成,导带主要由Mg的3s、3p及Si的3p态电子构成,静态介电常数为18.89,折射率为4.3460。掺Ag后Mg2Si为p型半导体,价带主要由Si的3p,Mg的3s、3p及Ag的3p、4d、5s态电子构成,静态介电常数为11.01,折射率为3.3175。掺Al后Mg2Si为n型半导体,导带主要由Mg的3s、3p,Si的3p及Al的3p态电子构成,Al的3s态电子贡献相对较小,静态介电常数为87.03,折射率为9.3289。通过掺杂有效调制了Mg2Si的电子结构,计算结果为Mg2Si光电材料的设计与应用提供了理论依据。
The energy band structures, density of states and optical properties of Mg2Si and Ag , Al-doped Mg2Si have been calculated systemically by first-principles pseudopotential method based on density functional theory （DFT）. The calculated results show that Mg2Si is an indirect semiconductor with the band gap of 0. 2994 eV, the valence bands of Mg2 Si are composed of Si 3 p, Mg 3 s, 3 p, the conduction bands are mainly composed of Mg 3 s, 3 p as well as Si 3p, the static dielectric function is 18.89, and the refractive index is 4. 3460. Ag-doped Mg2Si sample is io-type, the valence bands are composed of Si 3p, Mg 3s, 3p and Ag 3p, 4d and 5s, static dielectric function is 11.01, and the refractive index is 3. 3175 after doping Ag. Al-doped Mg2 Si sample is n-type, the conduction bands are composed of Mg 3s, 3p, Si 3p, and Al 3p, the static dielectric function is 87.03, and the refractive index is 9. 3289 after doping AI. The electronic structure of Mg2 Si can be modulated effectively by doping. The results offer theoretical data for the design and application of optoelectronic materials of Mg2 Si.
出处
《光学学报》
EI
CAS
CSCD
北大核心
2009年第1期229-235,共7页
Acta Optica Sinica
基金
国家自然科学基金(60566001
60766002)
贵州省优秀科技教育人才省长专项基金
省委组织部高层人才科研特助项目
贵阳市科学技术局大学生创业科技项目(6-5)
贵州大学研究生创新基金(省研理工2007003)资助课题
关键词
光学材料
MG2SI
光学性质
电子结构
掺杂
第一性原理
optical materials
Mg2Si
optical properties
electronic structure
doping
first principles
