采用基于密度泛函理论(DFT)的第一性原理计算方法, 计算了Mn4Si7及Mo掺杂Mn4Si7的电子结构和光学性质。计算结果表明Mn4Si7的禁带宽度Eg=0.804 eV, Mo掺杂Mn4Si7的禁带宽度Eg=0.636 eV。掺杂使得 Mn4Si7费米面附近的电子结构发生改变, 导带底由Γ点转移为Y 点向低能方向下偏移, 价带顶向高能方 向上偏移, 带隙变窄。计算还表明Mo掺杂 Mn4Si7使介电函数、折射率、吸收系数及光电导率等光学性质增加。

The electronic structure and optical properties of Mn4Si7 and Mn4Si7 doped by Mo were calculated by the density functional theory (DFT) based first-principles method. The calculation results show that the bandgap width of Mn4Si7 Eg=0.804 eV, and the bandgap width of Mo doped Mn4Si7 Eg=0.636 eV. Doping changes the electronic structure near the Fermi surface of Mn4Si7. The bottom of conduction band by Γ transfer to Y points to low-energy, under the direction of migration to the top of valence band offset to high-energy direction, narrow band gap. The calculation also shows that Mo doping Mn4Si7 increases the dielectric function, refractive index, absorption coefficient, photoconductivity and other optical properties.