• 文献标题:   Variable range hopping in graphene antidot lattices
  • 文献类型:   Article
  • 作  者:   PETERS EC, GIESBERS AJM, BURGHARD M
  • 作者关键词:   coulomb gap, electrical transport, graphene, variable range hopping
  • 出版物名称:   PHYSICA STATUS SOLIDI BBASIC SOLID STATE PHYSICS
  • ISSN:   0370-1972
  • 通讯作者地址:   Max Planck Inst Solid State Res
  • 被引频次:   14
  • DOI:   10.1002/pssb.201200177
  • 出版年:   2012

▎ 摘  要

We investigate the low temperature electrical transport mechanism in graphene antidot lattices. While the antidot diameter is kept constant at 50?nm, the center-to-center spacing between the antidots is varied from 80 to 200?nm in cubic arrangement. Our temperature dependent charge transport data reveal that electrical conduction in the samples is governed by variable range hopping (VRH) between localized states within a band gap. Upon decreasing the nanohole spacing the localization becomes stronger and the transport mechanism changes from 2D Mott VRH to EfrosShklovskii (ES VRH). Concomitantly, a soft gap emerges due to the stronger localization and the increased Coulomb interactions between the localized states, which are most likely located at the nanohole edges. The Coulomb gap (CG) decreases linearly with increasing charge carrier density. Stronger localization with an increased CG is observed for thermally annealed samples with reduced doping. (C) 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim