锐钛矿TiO_2及其掺Fe所导致的红移现象研究:赝势计算和紫外光谱实验

Anatase TiO_2 and red-shift introduced by doping with Fe:pseudopotential calculations and ultraviolet spectroscropy

采用平面波超软赝势方法研究了锐钛矿型TiO2 及Fe掺杂TiO2 的晶体结构和能带结构 ,计算表明Fe掺杂导致TiO2 电子局域能级的出现及禁带变窄 ,从而导致吸收光谱红移 .研究发现 ,t2g态在红移现象中起了重要作用 .紫外透射光谱实验证实了TiO2 掺Fe后吸收光谱红移和禁带变窄的理论预言 .

The crystal structure and electronic band structure of undoped and Fe-doped anatase TiO2 have been investigated by using the plane-wave ultrasoft pseudopotential method in the generalized gradient approximation (GGA). The calculation shows that Fe-doping introduces a localized level and narrowing of band gap in TiO2. The t(2g) state of the dopant plays a significant role in red-shift of spectrum. The previous prediction is confirmed by our experiment.