采用基于密度泛函理论第一性原理的方法,研究了Ta掺杂ZnO的电子结构和光学性质.计算结果表明:掺入Ta原子后,费米能级进入导带,随着掺杂浓度的增加,带隙逐渐变窄,介电函数虚部、吸收系数、反射率和折射率均发生明显变化,介电函数虚部和反射率均向高能方向移动,吸收边发生红移,从理论上指出了光学性质和电子结构的内在联系.
In this paper, the electronic structure and the optical properties of ZnO doped with Ta are calculated by the first-principles method based on the density function theory. The calculation results show that fermi energy levels enter into the conduction band after Ta-doped. With the increase of Ta concentration, the bandgap of ZnO is reduced and dielectric function imaginary part, absorption coefficient, the refractive index, and reflectivity are all changed significantly. The imaginary part of dielectric function and the reflectivity shift toward the higher-energy region. The absorption edge shifts to ward the red. The relationship between electronic structure and optical properties is pointed out in theory.