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Title: Carbon impurities on graphene synthesized by chemical vapor deposition on platinum

We report nanocrystalline carbon impurities coexisting with graphene synthesized via chemical vapor deposition on platinum. For certain growth conditions, we observe micron-size island-like impurity layers which can be mistaken for second graphene layers in optical microscopy or scanning electron microscopy. The island orientation depends on the crystalline orientation of the Pt, as shown by electron backscatter diffraction, indicating growth of carbon at the platinum surface below graphene. Dark-field transmission electron microscopy indicates that in addition to uniform single-crystal graphene, our sample is decorated with nanocrystalline carbon impurities with a spatially inhomogeneous distribution. The impurity concentration can be reduced significantly by lowering the growth temperature. Raman spectra show a large D peak, however, electrical characterization shows high mobility (∼8000 cm{sup 2}/Vs), indicating a limitation for Raman spectroscopy in characterizing the electronic quality of graphene.
Authors:
;  [1]
  1. Center for Nanophysics and Advanced Materials, University of Maryland, College Park, Maryland 20742-4111, USA and School of Physics, Monash University, 3800 Victoria (Australia)
Publication Date:
OSTI Identifier:
22308551
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Applied Physics; Journal Volume: 116; Journal Issue: 4; Other Information: (c) 2014 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; CARBON; CARRIER MOBILITY; CHEMICAL VAPOR DEPOSITION; DIFFRACTION; DISTRIBUTION; GRAPHENE; IMPURITIES; LAYERS; MONOCRYSTALS; NANOSTRUCTURES; OPTICAL MICROSCOPY; PLATINUM; RAMAN SPECTRA; RAMAN SPECTROSCOPY; SCANNING ELECTRON MICROSCOPY; SURFACES; TRANSMISSION ELECTRON MICROSCOPY