Mn2+、N2-共掺杂Zn2GeO4晶体电子结构和光学性质的研究

采用基于密度泛函理论的平面波超软赝势方法对本征Zn2GeO4，Mn2+掺杂Zn2GeO4，Mn2+/N2-共掺杂Zn2GeO4超晶胞进行了几何结构优化，计算了掺杂前后体系的晶格常数、能带结构、态密度和光学性质。结果表明，Mn离子掺入后，Mn离子3d轨道与O离子2p轨道之间有强烈的轨道杂化效应，掺杂系统不稳定，而Mn/N离子共掺后，Mn离子和N离子之间的吸引作用克服了Mn离子之间的排斥作用，能够明显地提高掺杂浓度和体系的稳定性。光学性质计算结果表明，Mn离子与N离子共掺杂能改善Zn2GeO4电子在低能区的光学跃迁特性，增强电子在可见光区的光学跃迁；吸收谱计算结果显示，Mn离子与N离子掺入后体系对低频电磁波吸收增加。

The electronic structures and optical properties in Mn2+/N2- co-doped Zn2GeO4

The structures, electronic and optical properties of pure Zn2GeO4, Mn-doped, N-doped and Mn/N co-doped Zn2GeO4 are studied by using the method of the local density approximation (LDA). These calculated results show that the doping of Mn atom induces the instability of the Zn2GeO4 system, N-doping can significantly increase the doping concentration and structure stability. In the optical property analysis, co-doping of Mn and N atoms can effectively improve the optical transition of Zn2GeO4 electron in the low energy region and the optical transition of the electron in the visible light region. The absorption spectrum calculation indicates that the co-doping of Mn and N can promote the promising absorption of low frequency electromagnetic waves.