Mn掺杂6H-SiC的第一性原理研究

本文通过密度泛函理论第一性原理平面波超软赝势计算方法计算了Mn掺杂6H-SiC的电子结构与光学性质。计算结果显示掺杂Mn后的6H-SiC为间接带隙p型半导体，且带隙较本征体有所降低，带隙由2.022 eV降为0.602 eV，电子从价带跃迁所需能量减少。掺杂后的Mn的3d能级在能带结构中以杂质能级出现，提高了载流子浓度，导电性增强。光学性质研究中，掺杂Mn后的介电函数虚部在低能处增加，电子激发态数量增多，跃迁概率增大。掺杂后的光吸收谱能量初值也较未掺杂的3.1 eV扩展到0 eV,反射谱发生红移。由于禁带宽度的降低使得光电导率起始范围得到扩展。

First-principles study of Mn-doped 6H-SiC

IIn this paper, the electronic structure and optical properties of manganese-doped 6H-SiC are calculated by the first-principles plane density wave theory in density functional theory. The calculation results show that after doping manganese 6H-SiC becomes an indirect band gap p-type semiconductor, and the band gap is lower than that of the intrinsic body. The band gap is reduced from 2.022 eV to 0.602 eV, and the energy required for electrons transition from the valence band is reduced. The doped Mn 3d energy levels appear as impurity levels in the energy band structure, so after doping Mn, the imaginary part of the dielectric function at low energy increases, the number of electronic excited states increases, and the transition probability is maximized. For the light absorption after doping, the initial value of the spectral energy is also extended to 0 eV from the undoped 3.1 eV, and the reflection spectrum is red-shifted. As the width of the forbidden band is reduced, the range of photoconductivity is expanded.