Zn掺杂锐钛矿TiO2的电子结构及光学性质的研究

采用基于密度泛函理论(DFT)的第一性原理对Zn掺杂锐钛矿TiO_2进行了结构优化,并对掺杂前后的能带结构、电子态密度和吸收光谱进行了计算。研究表明:Zn掺杂锐钛矿TiO_2体系为间接带隙半导体,在价带顶部引入了杂质能级,杂质能级主要由O-2p轨道和Zn-3d轨道贡献,杂质能级的引入增强了TiO_2对可见光区的响应,增大TiO_2的光吸收范围。实验结果表明:Zn掺杂使锐钛矿TiO_2吸收边红移,并能增强TiO_2的光电效应,可用于材料的光阴极保护。

Electronic structure and optical properties of Zn-doped anatase TiO2

The structure optimization, band structure, density of states and light absorption characteristics of Zn-doped anatase TiO₂ are studied with the first-principles calculation method based on density functional theory(DFT). The calculations results show that Zn-doped anatase TiO₂ is indirect band gap semiconductor, and the impurity energy level is introduced due to the couping between O-2p and Zn-3d, which can increase the TiO₂ absorption edge to the visible region, and therefore enlarge the absorption region of TiO₂. The experimental results show that Zn-doped TiO₂ leads to the red shift of the optical absorption edges to visible-light region and enhance thephotoelectric effect of anatase TiO₂. The effect is useful for the photocathode protection of photoelectric performance.