中文摘要：

The n-type Nb-doped SrTiO3 with different doping concentrations were studied by first principles calculations.The effects of Nb concentration on the formation enthalpy,electronic structure and optical property were investigated.Results show that Nb preferentially enters the Ti site in SrTiO3,which is in good agreement with the experimental observation.The Fermi level of Nb-doped SrTiO3 moves into the bottom of the conduction band,and the system becomes an n-type semiconductor.The effect of Nb-doping concentration on the conductivity was discussed from the microscopic point of view.Furthermore,the 1.11 at%Nb-doped SrTiO3 shows strong absorption in the visible light and becomes a very useful material for photo-catalytic activity.The 1.67 at% and 2.5 at%Nb-doped models will be potential transparent conductive materials.

英文摘要：

The n-type Nb-doped SrTiO3 with different doping concentrations were studied by first principles cal- culations. The effects of Nb concentration on the formation enthalpy, electronic structure and optical property were investigated. Results show that Nb preferentially enters the Ti site in SrTiO3, which is in good agreement with the experimental observation. The Fermi level of Nb-doped SrTiO3 moves into the bottom of the conduction band, and the system becomes an n-type semiconductor. The effect of Nb-doping concentration on the conductivity was discussed from the microscopic point of view. Furthermore, the 1.11 at% Nb-doped SrTiO3 shows strong absorp- tion in the visible light and becomes a very useful material for photo-catalytic activity. The 1.67 at% and 2.5 at% Nb-doped models will be potential transparent conductive materials.