• 文献标题:   Raman Spectroscopy of Folded and Scrolled Graphene
  • 文献类型:   Article
  • 作  者:   PODILA R, RAO R, TSUCHIKAWA R, ISHIGAMI M, RAO AM
  • 作者关键词:   folded graphene, raman spectroscopy, fermi velocity, graphene scroll
  • 出版物名称:   ACS NANO
  • ISSN:   1936-0851 EI 1936-086X
  • 通讯作者地址:   Clemson Univ
  • 被引频次:   35
  • DOI:   10.1021/nn302331p
  • 出版年:   2012

▎ 摘  要

Here we examine the effects of folding and scrolling on the Raman spectra of mechanically exfoliated single- and bilayer graphene prepared on SiO2 substrates. We find that incommensurate folding in bilayer graphene results in a shift of the second-order G' band frequency, similar to that observed in folded single-layer graphene due to fold-induced changes in the phonon/electronic energy dispersion. Importantly, we show that the contrasting Raman shifts reported for the G' band frequency in folded graphene can be rationalized by taking into account the relative strength of fold-induced electron/phonon renormalization. More interestingly, we find that curvature in scrolled graphene lifts the degeneracy of the G band and results in a splitting of the G band and the appearance of low-frequency radial breathing-like (RBLM) modes. This study highlights a variety of Raman signatures for fold-induced and curvature-induced graphene and sets the stage for further theoretical and experimental studies of these novel structures.