高氧空位浓度对金红石TiO2导电性能影响的第一性原理研究

采用基于密度泛函理论的平面波超软赝势方法研究了 纯的和不同高氧空位浓度金红石型TiO_2-x (x=0, 0.083, 0.125, 0.167, 0.25)超胞的能带结构分布、态密度分布.同时, 采用局域密度近似+U方法调准了带隙.结果表明, 高氧空位浓度越高, 金红石型TiO₂的最小带隙越变窄、电子有效质量越减小, 自由电子浓度越高, 电子迁移率越低、电导率越低.计算结果与实验结果的变化趋势相符合. 关键词： 高氧空位 2')" href="#">金红石型TiO₂ 电导率 第一性原理

Effects of the concentration of heavily oxygen vacancy of rutile TiO2 on electric conductivity performance from first principles study*

The band structures and the total densities of states of pure and the different concentrations of heavily oxygen vacancy of rutile TiO_2-x (x=0, 0.125, 0.25) supercell are studied by using the plane-wave ultrasoft pseudopotential method based on the the density functional theory. Local density approximation +U is used to correct band gaps. The results show that the higher the concentration of heavy oxygen vacancy, the narrower the gap of rutile TiO₂ is, the smaller the effective mass of electron is, the lower the electron mobility is, and the lower the electron conductivity is. The calculation results are in agreement with the experimental results.
Keywords： heavily oxygen vacancy 2')" href="#">rutile TiO₂ conductivity first-principles