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Title: Direct experimental evidence for the reversal of carrier type upon hydrogen intercalation in epitaxial graphene/SiC(0001)

Raman spectroscopy and scanning tunneling microscopy/spectroscopy measurements are performed to determine the atomic structure and electronic properties of H-intercalated graphene/SiC(0001) obtained by annealing the as-grown epitaxial graphene in hydrogen atmosphere. While the as-grown graphene is found to be n-type with the Dirac point (E{sub D}) at 450 and 350 meV below Fermi level for the 1st and 2nd layer, the H-intercalated graphene is p-type with E{sub D} at 320 and 200 meV above. In addition, ripples are observed in the now quasi-free standing graphene decoupled from the SiC substrate. This causes fluctuations in the Dirac point that directly follow the undulations of the ripples, resulting in electron and hole puddles in the H-intercalated graphene/SiC(0001)
Authors:
; ;  [1]
  1. Department of Physics, University of Wisconsin, Milwaukee, Wisconsin 53211 (United States)
Publication Date:
OSTI Identifier:
22280545
Resource Type:
Journal Article
Resource Relation:
Journal Name: Applied Physics Letters; Journal Volume: 104; 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; ANNEALING; CHARGE CARRIERS; CLATHRATES; ELECTRONS; EPITAXY; FERMI LEVEL; GRAPHENE; HOLES; HYDROGEN; INTERFACES; LAYERS; RAMAN SPECTROSCOPY; SCANNING TUNNELING MICROSCOPY; SILICON CARBIDES; SUBSTRATES