Ge，Al掺杂锰硅化合物Mn4Si7的第一性原理计算

基于密度泛函理论（DFT）的第一性原理计算方法，对本征Mn4Si7以及Ge，Al单掺杂和共掺杂Mn4Si7的晶体结构，能带结构，态密度以及光学性质进行了计算和分析.计算结果表明：本征态Mn4Si7的禁带宽度为0.810 eV，为直接带隙半导体材料，掺杂后晶体结构稍微变化，禁带宽度减小，且共掺杂时禁带宽度最小，电导率最好.Al以及Ge，Al共同掺杂时会产生杂质能级.掺杂后光子能量向低能级方向移动，光电导率，光吸收，反射系数都有所增大，说明掺杂改善了Mn4Si7的光学性质，从而可以提高光伏发电效率.

First-principles calculation of Ge, Al doped High manganese silicide Mn4Si7

Based on the first principles calculation method of density functional theory (DFT), the crystal structures, band structures, densities of states and optical properties of intrinsic Mn4Si7, Ge, Al single doped and Ge-Al co-doped Mn4Si7 are calculated and analyzed. The results show that: the band gap width of Mn4Si7 is 0.810 eV, which is a direct band gap semiconductor material. The crystal structure of Mn4Si7 changes slightly and the band gap width decreases after doping. The band gap width is the smallest and the conductivity is the best after Ge-Al co-doping. For Al doping and Ge-Al co-doping, impurity energy levels will be produced. After doping, the photon energy moves to the low energy level, and the photoconductivity, light absorption and reflection coefficient increase, indicating that the doping improves the optical properties of Mn4Si7 and hence its photovoltaic power generation efficiency.