Lin Wei, Zhang Yong-Fan, Li Yi, Ding Kai-Ning, Li Jun-Qian, Xu Yi-Jun
Department of Chemistry, Fuzhou University, Fuzhou, Fujian 350002, People's Republic of China.
J Chem Phys. 2006 Feb 7;124(5):054704. doi: 10.1063/1.2162896.
The Ti-doped SnO2(110) surface has been investigated by using first-principles method with a slab model. The geometrical optimizations and band-structure calculations have been performed for four possible doping models. Our results indicate that the substitution of Ti for sixfold-coordinated Sn atom at the top layer is most energetically favorable. Compared to the undoped surface, those Sn and O atoms located above Ti atom tend to move toward the bulk side. Besides the surface relaxations, the doping of Ti has significant influences on the electronic structures of SnO2(110) surface, including the value and position of minimum band gap, the components of valence and conduction bands, the distributions of the charge densities, and the work function of the surface. Furthermore, the effects introduced by the substitution of Ti atom observed in the experiments can be well explained when the sixfold-coordinated Sn atom at the first layer is replaced by Ti atom.
采用平板模型的第一性原理方法对掺钛的SnO₂(110)表面进行了研究。对四种可能的掺杂模型进行了几何优化和能带结构计算。我们的结果表明，在顶层用Ti取代六配位的Sn原子在能量上最为有利。与未掺杂表面相比，位于Ti原子上方的那些Sn和O原子倾向于向体相一侧移动。除了表面弛豫外，Ti的掺杂对SnO₂(110)表面的电子结构有显著影响，包括最小带隙的值和位置、价带和导带的组成、电荷密度分布以及表面功函数。此外，当第一层的六配位Sn原子被Ti原子取代时，可以很好地解释实验中观察到的Ti原子取代所引入的效应。
