• 文献标题:   Landscape of Charge Puddles in Graphene Nanoribbons on Hexagonal Boron Nitride
  • 文献类型:   Article
  • 作  者:   MAYAMEI Y, SHIN JC, WATANABE K, TANIGUCHI T, BAE MH
  • 作者关键词:   charge puddle, confinementgap energy, graphene nanoribbon, hexagonal boron nitride
  • 出版物名称:   PHYSICA STATUS SOLIDI BBASIC SOLID STATE PHYSICS
  • ISSN:   0370-1972 EI 1521-3951
  • 通讯作者地址:   Univ Sci Technol
  • 被引频次:   0
  • DOI:   10.1002/pssb.202000317 EA JUL 2020
  • 出版年:   2020

▎ 摘  要

Recently, graphene nanoribbons (GNRs) on hexagonal boron nitride (h-BN) substrates have been studied to develop high-mobility devices or devices based on a 1D Moire superlattice. For this purpose, a device-level understanding of the charge-puddle landscape of a GNR/h-BN structure is needed when the charge puddles function as scattering sources for mobile charge carriers. Here, a puddle landscape is constructed on the basis of an analysis of the temperature dependencies of the conductance of GNR/h-BN devices at various gate-voltage values. For low-, intermediate-, and high-temperature regions near the charge-neutral point (CNP), the puddle size (50-200 nm), distance between neighboring puddles (40-170 nm), and potential depth of the puddles (in a range of 10 meV) in similar to 100 nm wide GNR/h-BN devices are obtained on the basis of Coulomb blockade, 1D variable-range hopping, and thermally activated hopping, respectively. Based on the constructed puddle landscape, it is also concluded that the confinement-gap energy for an similar to 100 nm wide GNR is similar to that of the thermal activation energy near the CNP in the GNRs. The constructed puddle landscape for GNR/h-BN devices is consistent with that obtained from scanning tunneling microscopy observations of graphene on an h-BN structure.