Anomalous temperature-dependent shift in Fermi energy of epitaxial graphene on silicon carbide studied by photoluminescence spectroscopy and angle resolved photoemission spectroscopy

ORAL

Abstract

Photoluminescence spectroscopy (PL) and angle resolved photoemission spectroscopy (ARPES) have been used to study the interaction between epitaxially grown graphene and the silicon carbide substrate. We report evidence of an anomalous temperature dependent shift of the Fermi energy with a maximum at 65K. At this temperature, a similarly anomalous onset of the photoluminescence spectra is observed. These results are explained by the formation of a Schottky barrier at the graphene/silicon carbide interface, which is also responsible for the large electron doping of epitaxially grown graphene films. Finally, we discuss how the interaction between incident photons and the Schottky barrier could potentially be harnessed for future optical applications based on our results.

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Authors

  • Sebastien Lounis

    Graduate Group in Applied Science \& Technology, UC Berkeley

  • David Siegel

    Department of Physics, UC Berkeley, UC Berkeley / LBNL

  • Robert Broesler

    Department of Materials Science and Engineering, UC Berkeley

  • Eugene Haller

    Dept. of Materials Science and Engineering - UC - Berkeley, Materials Sciences Division - Berkeley National Lab, Department of Materials Science and Engineering, UC Berkeley, University of California, Berkeley and Lawrence Berkeley National Laboratory, Materials Science and Engineering, U. C., Berkeley; Materials Sciences Division, L. Berkeley National Lab, Lawrence Berkeley National Laboratory

  • Alessandra Lanzara

    Department of Physics, UC Berkeley, University of California at Berkeley; Lawrence Berkeley National Laboratory