• 文献标题:   Degenerate Perturbation in Band-Gap Opening of Graphene Superlattice
  • 文献类型:   Article
  • 作  者:   XIU SL, GONG L, WANG V, LIANG YY, CHEN G, KAWAZOE Y
  • 作者关键词:  
  • 出版物名称:   JOURNAL OF PHYSICAL CHEMISTRY C
  • ISSN:   1932-7447
  • 通讯作者地址:   Tohoku Univ
  • 被引频次:   13
  • DOI:   10.1021/jp5002572
  • 出版年:   2014

▎ 摘  要

We study the graphene band-gap engineering by introducing different defects, namely the defects breaking the inversion symmetry and the ones periodically patterning graphene into superlattice such as the regularly arranged antidots, etc. Comparing to the primitive unit cell of graphene, the pseudo-graphene superlattice, referred to the pristine graphene supercell, modulates the boundary condition accordingly. According to the energy band-folding picture, these superlattices can be categorized into two groups on the basis of the Dirac cone position. In some cases, the Dirac points K and K' in primitive cell are folded to the Gamma point of pseudo-superlattices. The coincidence of Dirac points with Gamma point results in the fourfold degeneracy. In these systems, a band gap at Gamma point can be opened by introducing periodically arranged defects such as the antidots, which could be easily utilized in experiment, for example, by making the graphene nanomesh through lithography technique. In the other cases, the twofold degenerate Dirac points remain nonequivalent with Gamma point in pseudo-superlattice, and the method to break the inversion symmetry could open their band gaps.