Direct experimental evidence for the reversal of carrier type upon hydrogen intercalation in epitaxial graphene/SiC(0001)
- Department of Physics, University of Wisconsin, Milwaukee, Wisconsin 53211 (United States)
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)
- OSTI ID:
- 22280545
- Journal Information:
- Applied Physics Letters, Journal Name: Applied Physics Letters Journal Issue: 4 Vol. 104; ISSN APPLAB; ISSN 0003-6951
- Country of Publication:
- United States
- Language:
- English
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