• 文献标题:   Deformation of graphene on an oxidizing nickel surface: the role of graphene layer number
  • 文献类型:   Article
  • 作  者:   GEORGE L, SHAINA PR, GUPTA A, DAS GUPTA N, JAISWAL M
  • 作者关键词:   graphene, raman spectroscopy, lattice strain, thermal oxidation, cvd graphene
  • 出版物名称:   MATERIALS RESEARCH EXPRESS
  • ISSN:   2053-1591
  • 通讯作者地址:   Indian Inst Technol Madras
  • 被引频次:   1
  • DOI:   10.1088/2053-1591/3/11/115016
  • 出版年:   2016

▎ 摘  要

Few-layer graphene grown on nickel substrates by chemical vapour deposition is typically characterised by thickness inhomogeneity. In this work, we investigate the thickness-dependent changes induced in graphene during the surface oxidation of the underlying metal. Temperature-dependent Raman spectroscopy and scanning electron microscopy are used to monitor the lattice strain and defect formation induced in graphene, as well as the oxidation of Ni surface. Significant lattice strain is induced in thin layers of graphene (1-2 layers) during the oxidation process, for T > 400 degrees C. This is followed by the formation of boundary-type defects, and graphene loses structural integrity. In contrast, lattice strain induced in thicker graphene (up to 7 layers) during the metal surface oxidation is quite subdued. These thicker layers de-pin and remain structurally intact even after the underneath metal surface has oxidized.