采用密度泛函理论下的第一性原理平面波赝势方法,研究了掺Ga对纤锌矿ZnO电子态密度和光学性质的影响.从晶体配位场理论分析了掺Ga前后ZnO的成键情况及态密度的变化.计算得到掺Ga后电子浓度为2.42×1021cm-3,ZnO的载流子浓度提高了104倍.比较分析掺Ga前后ZnO的介电函数、复折射率、吸收光谱和反射光谱可得,ZnO光吸收边向高能端移动,光学带隙增大.在可见光区,ZnO光吸收系数与反射率减小,光透过率显著提高,使ZnO:Ga成为理想的透明导电材料.
The electronic structures and optical properties of pure and Ga-doped wurtzite ZnO are studied by using first-principles plane wave pseudopotential method based on the density functional theory. The bonding of ZnO and changes in density of states are analyzed using of the crystal ligand field theory. Electron concentration is 2. 42 × 1021 cm-3 by calculation,and carrier concentration of ZnO is raised 104 fold by doping Ga. Analysis of dielectric function,refractive index,absorption spectrum and reflectance spectrum of pure and Ga-doped ZnO shows that the optical absorption edge moving to high energy leads optical gap to broaden. In the visible light region,optical absorption coefficient and reflectivity are reduced and optical transmittance is increased significantly. Optical properties of ZnO are improved effectively by Ga doping.