Sb、Ta掺杂对铌酸钾钠性能的影响

该文基于密度泛函的第一性原理计算Sb、Ta掺杂铌酸钾钠的电子结构和光学性质。通过计算发现未掺杂的铌酸钾钠带隙为2.188 eV,Sb掺杂铌酸钾钠带隙变为2.213 eV,而Ta掺杂铌酸钾钠带隙为2.098 eV。通过分析Sb、Ta掺杂铌酸钾钠的态密度发现Sb掺杂后在-10 eV左右出现新的波,位于-5.508~0.496 eV的波主要由Ta的d轨道和K的s轨道杂化而成。Sb、Ta单掺杂与共掺杂铌酸钾钠均使介电函数的实部ε_(1)(ω)分别提高,但函数整体向低能级移动,虚部在0~3.93 eV产生新的峰且向低能级移动。Ta掺杂时能量损失函数峰值提高,Sb掺杂则减少。

In this paper,the electronic structure and optical properties of Sb and Ta doped potassium sodium niobate are calculated based on First Principle of density functional theory.Through calculations,it was found that the band gap of undoped potassium sodium niobate was 2.188 eV,the band gap of Sb-doped potassium sodium niobate became 2.213 eV,and the band gap of Ta-doped potassium sodium niobate was 2.098 eV.By analyzing the density of states of Sb-Ta-doped potassium sodium niobate,it was found that a new wave appeared at around-10 eV after Sb doping,and the wave at-5.508~0.496 eV was mainly composed of the hybridization of Ta's d orbital and K's s orbital.Both single doping and co-doping of potassium and sodium niobate of Sb and Ta increase the real partε_(1)(ω)of the dielectric function respectively,but the entire function moves towards the low level,and the imaginary part produces a new peak around 0~3.93 eV and moves towards the low level.The peak energy loss function peak increases when Ta is doped,but decreases when Sb is doped.