物理化学学报 >> 2006, Vol. 22 >> Issue (01): 76-81.doi: 10.3866/PKU.WHXB20060115

研究论文 上一篇    下一篇

SnO2(110)弛豫表面构型与电子结构的第一性原理研究

林伟; 章永凡; 李奕; 陈勇; 李俊篯   

  1. 福州大学化学系, 福州 350002; 中国科学院福建物质结构研究所, 结构化学国家重点实验室, 福州 350002
  • 收稿日期:2005-06-21 修回日期:2005-08-31 发布日期:2006-01-15
  • 通讯作者: 章永凡 E-mail:zhangyf@fzu.edu.cn

First Principle Studies on the Geometry and Electronic Structures of the SnO2(110) Surface

LIN Wei; ZHANG Yong-fan; LI Yi; CHEN Yong; LI Jun-qian   

  1. Department of Chemistry, Fuzhou University, Fuzhou 350002, P. R. China; State Key Laboratory of Structural Chemistry, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou 350002, P. R. China
  • Received:2005-06-21 Revised:2005-08-31 Published:2006-01-15
  • Contact: ZHANG Yong-fan E-mail:zhangyf@fzu.edu.cn

摘要: 采用基于第一性原理的密度泛函方法对SnO2(110)表面的构型和电子结构进行了系统研究. 结果表明, 与理想表面相比, 表面弛豫导致表层五配位Sn原子向体相方向位移, 六配位Sn原子以及表面氧原子往真空方向移动, 而桥氧原子位置基本保持不变. 当表面厚度小于3 nm时, 表面能和表层原子的弛豫大小随着层数的增加出现振荡现象. 由能带计算结果得知, 以桥氧的2py/2i>pz轨道为主要成分的能带出现在体相的带隙中. 进一步考察了弛豫对表面电子结构的影响.

关键词: 二氧化锡, 表面弛豫, 能带结构, 密度泛函理论, 表面态

Abstract: The geometry and electronic structures of the SnO2(110) surface have been investigated by using the first-principle method. Compared to an ideal surface, the five-fold and six-fold Sn atoms at the top layer shift inwards and outwards, respectively. For the surface oxygen atoms, the in-plane oxygen atoms move outwards, while the displacement of bridged oxygen can be neglectable. When the thickness of slab is smaller than 3 nm, the oscillations of surface energy and the displacements of surface atoms as a function of the number of layers are observed. The results of band structure calculations show that the energy bands mainly originated from the 2i>py/2i>pz orbitals of the bridged oxygen appear in the bottom of the band gap of bulk. Furthermore, the influences of the surface relaxation on the electronic properties of SnO2(110) surface are also discussed.

Key words: Tin dioxide, Surface relaxation, Band structures, Density functional theory, Surface state