Al、F掺杂锐钛矿相TiO_2电子结构的第一性原理计算

First-principle Calculation of Electronic Structure of Anatase TiO_2 Doped with Al or F

采用基于密度泛函理论的第一性原理平面波超软赝势方法计算研究了Al掺杂、F掺杂、Al-F共掺杂锐钛矿相TiO2的能带结构、电子态密度和吸收光谱。计算结果表明:掺杂TiO2的禁带宽度均有不同程度的减小,其中Al掺杂TiO2禁带宽度减小幅度最大;掺杂TiO2的吸收边均出现不同程度的蓝移,其中F掺杂TiO2吸收边的蓝移程度最大;在可见光区,F掺杂TiO2的吸收能力明显增强,Al掺杂TiO2居中,而Al-F共掺杂TiO2未增强。

The energy band structures, density of electronic states and absorption spectra of Al-doped, F-doped and Al-F co-doped anatase TiO2 were calculated using the first-principle plane wave ultra-soft pseudo-potential method based on the density functional theory. The results indicate that the band gaps of all the doped TiO2 decrease to different extent,and that of Al-doped TiO2 decreases most obviously. All the doped anatase TiO2 show blue shift of absorption edge at different level,and among them the blue shift of F-doped TiO2 is the maximum. In visible light region, there is notable increase of absorptivity of F-doped TiO2 and the absorptivity of Al-doped TiO2 is moderately increased, while the absorptivity of A1-F codoped TiO2 is not increased.