双氮原子掺入二氧化钛电子结构的第一原理研究

First-principles study on the structural and electronic properties of double N atoms doped-rutile TiO_2

采用基于第一性原理的平面波超软赝势方法计算研究了双N原子掺入金红石相TiO_2的几何结构和电子结构.通过比较三种可能的掺杂方式的总能发现,两个氮原子占据两个相邻的B原子位置时具有最稳定的结构.电子结构分析表明,双N原子掺杂TiO_2出现了杂质能级,三种结构的能带间隙均减小,其中杂质原子最近邻占位时,带隙最小,随着两个杂质原子的距离增大,带隙会逐渐变大.

In this paper, the electronic structure of rutile TiO2 doped with double nitrogen atoms was studied by the plane-wave ultrasoft pseudopotential method based on the first-principles density functional theory. It has been used to analyze the effect of three doping positions of double N on the relevant band structure. The calculation demonstrates that there exist additional states in the band gap when doping of the rutile TiO2 with N atoms, and the gap become narrowing. The results imply that the doped two N atoms in the adjacent position form a more intermediate stable level, and the total energy is the minimum.