金红石型TiO2点缺陷性质的第一性原理研究

First-principles study of point defects in rutile TiO_2

本文运用基于局域密度泛函和赝势的第一性原理方法研究了金红石相TiO2点缺陷的电子性质,结果表明氧空位缺陷使晶体的费米能量升高,在能隙中没有产生杂质能级.钛空位缺陷使晶体的费米能量降低,并在价带顶部产生了一个杂质能级,与价带顶能量相差约0.4 eV.本文还计算了金红石相TiO2在具有氧空位和钛空位点缺陷情况下的键长变化、态密度和电荷布居状况.

Point defects in TiO2 in rutile phase are investigated by using first-principles pseudopotential calculations based on density-functional theory （DFT）. By comparing with perfect crystal, it is found that in the case of oxygen vacancy Fermi energy goes up and no defect level appears in the gap and in the case of titanium vacancy Fermi energy goes down and a defect level appears in the gap, which is about 0.4eV above the top of value band. The bond length, density of states and population of TiO2 with oxygen vacancy and titanium vacancy have also been analyzed in this paper.