采用基于密度泛函理论的第一性原理研究了 N掺杂, Nd掺杂,和Nd/N共掺杂对锐钛矿相TiO2晶格参数、能带结构、电荷布居、电子态密度和光吸收性质的影响.结果表明,杂质的引入不同程度的改变了TiO2的晶格参数,Nd的掺杂使TiO6八面体畸变最大;N掺杂TiO2使带隙宽度减小,且在价带顶出现杂质能级;Nd掺杂和Nd/N共掺杂不仅使TiO2带隙宽度减小并在其价带和导带之间出现了空带,空带主要由Nd原子的4f轨道能级所贡献;由于禁带宽度的减小和杂质能级的出现使得掺杂后TiO2的吸收光谱的吸收边向可见光方向移动,增加了物质对光吸收的响应范围.
The lattice parameters, energy band structures, density of states and optical absorption spectra of N-doped, Nd-doped and Nd/N co-doped anatase TiO2 were calculated by the first-principles based on the density functional theory.The calculated results indicate that these three kinds of doping all induce lattice distortion for TiO2 with the biggest distortion of TiO6 octahedron after being doped by Nd,N doping introduces an impurity energy level above the maximum valence band and decreases the band gap of TiO2.Nd doping introduces empty band in the forbidden band of TiO2, which is mainly composed of Nd4f orbital.The experimental results for the red-shift of the absorption edge of TiO2 by the Nd doping can be explained perfectly from the decrease of the band gap.
参考文献
- 下载量()
- 访问量()
- 您的评分：
-
10%
-
20%
-
30%
-
40%
-
50%