• 文献标题:   Graphene-boron nitride superlattices: the role of point defects at the BN layer
  • 文献类型:   Article
  • 作  者:   MATOS MJS, MAZZONI MSC, CHACHAM H
  • 作者关键词:   graphene, superlattice, density functional theory, boron nitride
  • 出版物名称:   NANOTECHNOLOGY
  • ISSN:   0957-4484 EI 1361-6528
  • 通讯作者地址:   Univ Fed Minas Gerais
  • 被引频次:   15
  • DOI:   10.1088/0957-4484/25/16/165705
  • 出版年:   2014

▎ 摘  要

We investigate, by means of first-principles calculations, the role of hBN point defects on the energetical stability and electronic structure of heterostructures composed of graphene atop hBN, rotated at angles of 13.17 degrees, 9.43 degrees and 7.34 degrees. We consider, as possible point defects, boron and nitrogen vacancies and antisites, substitutional oxygen at the nitrogen site O-N, substitutional carbon dimers, and nitrogen interstitials. The electronic and structural properties of all defects were analyzed. Among these, the most stable is O-N, with negative formation energies at several possible rotation angles and chemical environments. Under such conditions, O-N doping can raise the Fermi level of the neutral system by as much as 1 eV relative to graphene's Dirac point, reaching the band crossing between adjacent Dirac cones at the M point of the heterostructure Brillouin zone. This could lead to interesting electronic transport properties without the need for electrostatic doping.