• 文献标题:   Electric field effect in boron and nitrogen doped graphene bilayers
  • 文献类型:   Article
  • 作  者:   NEMNES GA, MITRAN TL, MANOLESCU A, DRAGOMAN D
  • 作者关键词:   graphene bilayer, field effect, effective doping
  • 出版物名称:   COMPUTATIONAL MATERIALS SCIENCE
  • ISSN:   0927-0256 EI 1879-0801
  • 通讯作者地址:   Univ Bucharest
  • 被引频次:   3
  • DOI:   10.1016/j.commatsci.2018.08.054
  • 出版年:   2018

▎ 摘  要

Unlike single layer graphene, in the case of AB-stacked bilayer graphene (BLG) one can induce a non-zero energy gap by breaking the inversion symmetry between the two layers using a perpendicular electric field. This is an essential requirement in field-effect applications, particularly since the induced gap in BLG systems can be further tuned by the magnitude of the external electric field. Doping is another way to modify the electronic properties of graphene based systems. We investigate here BLG systems doped with boron and nitrogen in the presence of external electric field, in the framework of density functional theory (DFT) calculations. Highly doped BLG systems are known to behave as degenerate semiconductors, where the Fermi energy depends on the doping concentration but, in addition, we show that the electronic properties drastically depend also on the applied electric field. By changing the magnitude and the orientation of the electric field, the gap size and position relative to the Fermi level may be tuned, essentially controlling the effect of the extrinsic doping. In this context, we discuss in how far the external electric field may suitably adjust the effective doping and, implicitly, the conduction properties of doped BLG systems.