• 文献标题:   Adsorption configurations and scanning voltage determined STM images of small hydrogen clusters on bilayer graphene
  • 文献类型:   Article
  • 作  者:   CAO TF, HUANG LF, ZHENG XH, ZHOU WH, ZENG Z
  • 作者关键词:  
  • 出版物名称:   JOURNAL OF CHEMICAL PHYSICS
  • ISSN:   0021-9606 EI 1089-7690
  • 通讯作者地址:   Chinese Acad Sci
  • 被引频次:   2
  • DOI:   10.1063/1.4832040
  • 出版年:   2013

▎ 摘  要

By density functional theory calculations, the scanning tunneling microscopy (STM) images of various hydrogen clusters adsorbed on bilayer-graphene are systematically simulated. The hydrogen configurations of the STM images observed in the experiments have been thoroughly figured out. In particular, two kinds of hydrogen dimers (ortho-dimer, para-dimer) and two kinds of tetramers (tetramer-A, -B) are determined to be the hydrogen configurations corresponding to the ellipsoidal-like STM images with different structures and sizes. One particular hexamer (hexamer-B) is the hydrogen configuration generating the star-like STM images. For each hydrogen cluster, the simulated STM images show unique voltage-dependent features, which provides a feasible way to determine hydrogen adsorption states on graphene or graphite surface in the experiments by varying-voltage measurements. Stability analysis proves that the above determined hydrogen configurations are quite stable on graphene, hence they are likely to be detected in the STM experiments. Consequently, through systematic analysis of the STM images and the stability of hydrogen clusters on bilayer graphene, many experimental observations have been consistently explained. (C) 2013 AIP Publishing LLC.