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化学学报
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化学学报 ›› 2010, Vol. 68 ›› Issue (16): 1589-1596. 上一篇    下一篇

研究论文

乙炔和乙烯分子在Ge(001)表面吸附的第一性原理研究

范晓丽*，闵家祥，孙承才，池琼，程千忠   

  1. (西北工业大学材料学院 西安 710072)
  • 投稿日期:2010-01-26 修回日期:2010-03-15 发布日期:2010-04-22
  • 通讯作者: 范晓丽 E-mail:xlfan@nwpu.edu.cn
  • 基金资助:

    自然科学基金;陕西省自然科学基金

Density Functional Studies on the Adsorption of Acetylene and Ethylene Molecules on Ge(001) Surface

FAN Xiao-Li, MIN Jia-Xiang, SUN Cheng-Cai, CHI Qiong, CHENG Qian-Zhong   

  1. (School of Material Science and Engineering, Northwestern Polytechnical University, Xi'an 710072)
  • Received:2010-01-26 Revised:2010-03-15 Published:2010-04-22
  • Contact: Xiao-Li FAN E-mail:xlfan@nwpu.edu.cn

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被引次数

3 | 1

采用基于密度泛函理论的第一性原理方法和平板模型研究了乙炔和乙烯分子在Ge(001)表面的吸附构型和电子结构. 通过系统考察一系列可能存在的吸附方式, 结果表明, 在0.5 monolayer(ML)覆盖度时, 两种分子的di-σ吸附构型最为稳定; 在覆盖度为1.0 ML时的最稳定吸附方式是paired end-bridge构型. 能带结构分析结果可知, 吸附构型以及吸附分子的覆盖度均对Ge(001)表面带隙有较大影响, 其原因在于费米能级附近的能带主要来自表面二聚体的Ge原子, 它们与表面Ge原子的配位环境密切相关, 而后者又取决于分子的吸附方式和覆盖度. 对于相同的吸附方式, 乙烯和乙炔分子具有类似的吸附行为和电子结构. 此外, 还进一步与Si(001)表面的研究结果进行对比.

关键词: 密度泛函理论, 乙炔分子, 乙烯分子, Ge(001)表面, 吸附结构, 能带结构

By using the first-principles method based on density functional theory and slab model, we have studied the atomic geometries and electronic structures of adsorptions of ethylene and acetylene on Ge(001) surface. By studying a series of possible adsorption configurations for both the acetylene and ethylene, we found that di-σ configuration is the most stable one at coverage of 0.5 ML (monolayer), while paired end-bridge configuration is the most stable one at the coverage of 1.0 ML. Our study of the electronic band structure show that both the adsorption configuration and coverage are important factors for the band structure near the Fermi level, the reason is that the surface states near the Fermi level are from the Ge atoms of the dimer on the surface, and mainly determined by the coordinate environment of Ge atoms, which are related to the adsorption model and coverage. While for the same adsorption model, the adsorption configuration and electronic structure are similar for both the ethylene and acetylene molecules. Moreover, the adsorption on Ge(001) and Si(001) have been compared for the two molecules.

Key words: density functional theory, acetylene molecule, ethylene molecule, Ge(001) surface, adsorption configuration, electronic band structure