重氧空位对金红石型和锐钛矿型TiO_2导电性能影响的模拟计算

Effect of concentration of heavy oxygen vacancy in rutile and anatase(TiO_2) on electric conductivity performance studied by simulation and calculation

基于密度泛函理论框架下的第一性原理平面波超软赝势方法,构建了未掺杂与相同重氧空位金红石型和锐钛矿型TiO1.9375超胞模型,分别对模型进行了几何结构优化、能带结构分布和态密度分布的计算.结果表明,氧空位后金红石型和锐钛矿型TiO2体系体积均变大,同时,锐钛矿型TiO1.9375超胞的稳定性、迁移率以及电导率均高于金红石型TiO1.9375超胞.计算结果和实验结果相一致.

The pure and heavy oxygen vacancy for both rutile and anatase supercell models of TiO1.9375 were structured by using first-principles plane-wave ultrasoft pseudopotential method based on the density functional theory, the geometry optimizations, band structures, and density of states of these models were calculated. Results show that the volumes become greater for both heavy oxygen vacancy rutile and anatase, meanwhile, all of the stability, mobility, and conductivity of anatase supercell model of TiO1.9375 ore greater than the rutile supercell model, which are in agreement with the experimental results.