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Title: Evaluating the Sources of Graphene’s Resistivity Using Differential Conductance

We explore the contributions to the electrical resistance of monolayer and bilayer graphene, revealing transitions between different regimes of charge carrier scattering. In monolayer graphene at low densities, a nonmonotonic variation of the resistance is observed as a function of temperature. Such behaviour is consistent with the influence of scattering from screened Coulomb impurities. At higher densities, the resistance instead varies in a manner consistent with the influence of scattering from acoustic and optical phonons. The crossover from phonon-, to charged-impurity, limited conduction occurs once the concentration of gate-induced carriers is reduced below that of the residual carriers. In bilayer graphene, the resistance exhibits a monotonic decrease with increasing temperature for all densities, with the importance of short-range impurity scattering resulting in a “universal” density-independent (scaled) conductivity at high densities. At lower densities, the conductivity deviates from this universal curve, pointing to the importance of thermal activation of carriers out of charge puddles. These various assignments, in both systems, are made possible by an approach of “differential-conductance mapping”, which allows us to suppress quantum corrections to reveal the underlying mechanisms governing the resistivity.
Authors:
 [1] ;  [2] ;  [2] ; ORCiD logo [2] ;  [3] ;  [3] ;  [2] ;  [4] ; ORCiD logo [5]
  1. King Mongkut’s Institute of Technology Ladkrabang, Bangkok (Thailand). Department of Physics
  2. University at Buffalo, the State University of New York, Buffalo, NY (United States). Department of Electrical Engineering
  3. University at Buffalo, the State University of New York, Buffalo, NY (United States). Department of Physics
  4. Uppsala Univ. (Sweden). Department of Physics and Astronomy
  5. University at Buffalo, the State University of New York, Buffalo, NY (United States). Department of Electrical Engineering; Chiba University (Japan). Graduate School of Advanced Integration Science
Publication Date:
Grant/Contract Number:
FG02-04ER46180
Type:
Accepted Manuscript
Journal Name:
Scientific Reports
Additional Journal Information:
Journal Volume: 7; Journal Issue: 1; Journal ID: ISSN 2045-2322
Publisher:
Nature Publishing Group
Research Org:
State Univ. of New York (SUNY), Plattsburgh, NY (United States)
Sponsoring Org:
USDOE Office of Science (SC), Basic Energy Sciences (BES) (SC-22). Materials Sciences & Engineering Division
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE; 42 ENGINEERING; 71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS; Electronic properties; Two-dimensional materials
OSTI Identifier:
1429882