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Title: Charged impurity-induced scatterings in chemical vapor deposited graphene

We investigate the effects of defect scatterings on the electric transport properties of chemical vapor deposited (CVD) graphene by measuring the carrier density dependence of the magneto-conductivity. To clarify the dominant scattering mechanism, we perform extensive measurements on large-area samples with different mobility to exclude the edge effect. We analyze our data with the major scattering mechanisms such as short-range static scatters, short-range screened Coulomb disorders, and weak-localization (WL). We establish that the charged impurities are the predominant scatters because there is a strong correlation between the mobility and the charge impurity density. Near the charge neutral point (CNP), the electron-hole puddles that are induced by the charged impurities enhance the inter-valley scattering, which is favorable for WL observations. Away from the CNP, the charged-impurity-induced scattering is weak because of the effective screening by the charge carriers. As a result, the local static structural defects govern the charge transport. Our findings provide compelling evidence for understanding the scattering mechanisms in graphene and pave the way for the improvement of fabrication techniques to achieve high-quality CVD graphene.
Authors:
;  [1] ;  [2] ;  [1] ;  [3] ; ;  [1] ;  [3]
  1. Department of Physics, National Tsing Hua University, Hsinchu 30013, Taiwan (China)
  2. Department of Physics, Tamkang University, Tamsui Dist., New Taipei 25137, Taiwan (China)
  3. (China)
Publication Date:
OSTI Identifier:
22266097
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Applied Physics; Journal Volume: 114; Journal Issue: 23; Other Information: (c) 2013 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS; CARRIER DENSITY; CHARGE CARRIERS; CHARGE TRANSPORT; CHEMICAL VAPOR DEPOSITION; CORRELATIONS; FABRICATION; GRAPHENE; HOLES; IMPURITIES; SCATTERING