• 文献标题:   Conductivity of epitaxial and CVD graphene with correlated line defects
  • 文献类型:   Article
  • 作  者:   RADCHENKO TM, SHYLAU AA, ZOZOULENKO IV
  • 作者关键词:   epitaxial cvd graphene, line point defect, quantum transport, numerical simulation
  • 出版物名称:   SOLID STATE COMMUNICATIONS
  • ISSN:   0038-1098 EI 1879-2766
  • 通讯作者地址:   NASU
  • 被引频次:   9
  • DOI:   10.1016/j.ssc.2014.07.012
  • 出版年:   2014

▎ 摘  要

Transport properties of single-layer graphene with correlated one-dimensional defects are studied theoretically using the computational model within the time-dependent real-space Kubo-Greenwood formalism. Such defects are present in epitaxial graphene, comprising atomic terraces and steps due to the substrate morphology, and in polycrystalline chemically vapor-deposited (CVD) graphene due to the grain boundaries, composed of a periodic array of dislocations, or quasi-periodic nanoripples originated from the metal substrate. The extended line defects are described by the long-range Lorentzian-type scattering potential. The dc conductivity is calculated numerically for different cases of distribution of line defects. This includes a random (uncorrelated) and a correlated distribution with a prevailing direction in the orientation of lines. The anisotropy of the conductivity along and across the line defects is revealed, which agrees with experimental measurements for epitaxial graphene grown on SiC. We performed a detailed study of the conductivity for different defect correlations, introducing the correlation angle alpha(max)-the maximum possible angle between any two lines. We find that for a given electron density, the relative enhancement of the conductivity for the case of fully correlated line defects in comparison to the case of uncorrelatecl ones is larger for a higher defect density. Finally, we, for the first time, study the conductivity of realistic samples where both extended line defects and point-like scatterers such as adatoms and charged impurities are presented. (C) 2014 Elsevier Ltd. All rights reserved,