光学学报, 2009, 29 (1): 229, 网络出版: 2009-02-10
掺杂Mg2Si电子结构及光学性质的第一性原理计算 下载: 596次
First-Principles Calculation of Electronic Structure and Optical Properties of Mg2Si with Doping
光学材料 光学性质 电子结构 掺杂 第一性原理 optical materials Mg2Si Mg2Si optical properties electronic structure doping first principles
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。
Abstract
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 Mg2Si are composed of Si 3p, Mg 3s, 3p, the conduction bands are mainly composed of Mg 3s, 3p as well as Si 3p, the static dielectric function is 18.89, and the refractive index is 4.3460. Ag-doped Mg2Si sample is p-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 Mg2Si 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 Al. The electronic structure of Mg2Si can be modulated effectively by doping. The results offer theoretical data for the design and application of optoelectronic materials of Mg2Si.
陈茜, 谢泉, 杨创华, 赵凤娟. 掺杂Mg2Si电子结构及光学性质的第一性原理计算[J]. 光学学报, 2009, 29(1): 229. Chen Qian, Xie Quan, Yang Chuanghua, Zhao Fengjuan. First-Principles Calculation of Electronic Structure and Optical Properties of Mg2Si with Doping[J]. Acta Optica Sinica, 2009, 29(1): 229.