W-N共掺杂锐钛矿相TiO_2的第一性原理计算

First Principle Calculation of W-N Co-doped Anatase TiO_2

利用基于密度泛函理论的第一性原理方法对W-N共掺杂锐钛矿相TiO2的能带结构、电子态密度及吸收光谱进行计算.结果表明,W-N共掺杂未改变锐钛矿相TiO2的禁带宽度,仅在TiO2价带顶附近引入N的2p杂质能级,并且掺杂系统的费米能级处于导带之内；W的5d轨道主要对TiO2的价带底下边沿和导带有贡献,N的2p轨道主要对TiO2的价带顶上边沿和禁带内的孤立能级有贡献；W-N共掺杂增强了锐钛矿相TiO2在340～800 nm波长范围内的光吸收能力.

The band structure,electronic density of states and absorption spectrum of W—N co-doped anatase TiO2 were calculated using first principle based on the density functional theory.The results indicate that W—N co-doping does not change the band gap of anatase TiO2,while N 2p doping energy level is incorporated into the band gap above the valence band maximum,and its Fermi energy level is located at the conduction band.W 5d orbital provides contributions to the bottom edge of valence band and conduction band,whereas N 2p contributes its orbital to the upper edge of valence band maximum and the isolated doping energy level located in the band gap.W—N co-doping enhances the absorption ability of anatase TiO2 in the wave length range from 340 to 800 nm.