非金属元素C、N、F掺杂锐钛矿型TiO_2的缺陷形成能和电子性质

Defect formation energy and electronic properties of anatase TiO_2 doped with C,N,F

非金属杂质掺杂TiO2半导体改善对可见光区域的光催化性质是近年来的一个研究热点,但相关杂质缺陷的形成能研究却不多。通过基于密度泛函理论的平面波超软赝势方法,研究了非金属元素C、N、F掺杂锐钛矿型TiO2之后的缺陷形成能与电子性质。结果表明,3种元素掺杂进入TiO2后缺陷形成能的大小排序为C>N>F,说明F元素最容易掺杂进入TiO2晶格。但是掺入F元素后对TiO2禁带宽度的改变不大,在提高TiO2对可见光的响应方面F元素的效果不如N、C两种元素。因此,对于掺杂来改善TiO2对可见光的响应方面,N元素比C、F的效果更好。

Recently,non-metallic impurities doped TiO2 semiconductor to improve photocatalytic properties of visible light region was a research focus,but not many related defect formation energy research.In this paper,the defect formation energy and the electronic properties of anatase TiO2 was studied by plane wave pseudopotential method based on the density functional theory.After the three elements doped into TiO2,the order of the defect formation energy was CNF.The results show that F was most easily doped into the titanium dioxide lattice,but the change of band gap was very small.So F-doped was not as good as N-doped and C-doped in response effect of visible light.In view of the above two reasons,N was the best of the three dopants in improving visible light response.