过渡金属元素(X=Cr,Mn,Co,Ni,Zn,Zr,Nb,Ta)掺杂立方BaTiO_(3)的电子结构及光学性质的第一性原理研究

First Principles Study on Electronic Structure and Optical Properties of Transition Metal Elements(X=Cr,Mn,Co,Ni,Zn,Zr,Nb,Ta)Doped Cubic BaTiO_(3)

本工作通过密度泛函理论(DFT)的第一性原理方法研究了过渡金属元素(X=Cr,Mn,Co,Ni,Zn,Zr,Nb,Ta)掺杂立方相BaTiO_(3)的电子结构和光学性质。结果表明:掺杂Cr、Mn、Nb、Ta原子后,禁带宽度消失,体系导带底部向低能方向移动,费米能级穿过导带,体现出n型半导体的特征;掺杂Co、Ni和Zn原子后,禁带宽度消失,体系价带顶部向高能方向移动,费米能级穿过价带,体现出p型半导体的特征。在光学性质上,入射光为零的情况下未掺杂BaTiO_(3)的静态介电常数为6.464,掺杂低浓度的Cr、Mn、Co、Ni、Zn后,静态介电常数增大;掺杂低浓度的Zr、Nb、Ta后,静态介电常数减小。

In this work,the electronic structure and optical properties of transition metal elements(X=Cr,Mn,Co,Ni,Zn,Zr,Nb,TA)doped cubic BaTiO_(3)are studied by the first principle method of density functional theory(DFT).The results show that after doping Cr,Mn,Nb and Ta atoms,the band-gap disappears,the bottom of the conduction band moves to the low energy direction,and the Fermi level passes through the conduction band,reflecting the characteristics of n-type semiconductor;after doping Co,Ni and Zn atoms,the band-gap disappears,the top of the valence band moves towards the high energy direction,and the Fermi level passes through the valence band,reflecting the characteristics of p-type semiconductors.In terms of optical properties,when the incident light is zero,the static dielectric constant of undoped BaTiO_(3)is 6.464.after doping low concentrations of Cr,Mn,Co,Ni and Zn,the static dielectric constant increases;after doping low concentrations of Zr,Nb and Ta,the static dielectric constant decreases.