Atomic-scale characterization of the interfacial phonon in graphene/SiC

Emi Minamitani, Ryuichi Arafune, Thomas Frederiksen, Tetsuya Suzuki, Syed Mohammad Fakruddin Shahed, Tomohiro Kobayashi, Norifumi Endo, Hirokazu Fukidome, Satoshi Watanabe, Tadahiro Komeda

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7 Citations (Scopus)

Abstract

Epitaxial graphene on SiC that provides wafer-scale and high-quality graphene sheets on an insulating substrate is a promising material to realize graphene-based nanodevices. The presence of the insulating substrate changes the physical properties of free-standing graphene through the interfacial phonon, e.g., limiting the mobility. Despite such known impacts on the material properties, a complete and microscopic picture is missing. Here, we report on atomically resolved inelastic electron tunneling spectroscopy (IETS) with a scanning tunneling microscope for epitaxial graphene grown on 4H-SiC(0001). Our data reveal a strong spatial dependence in the IETS spectrum, which cannot be explained by intrinsic graphene properties. We show that this variation in the IETS spectrum originates from a localized low-energy vibration of the interfacial Si atom with a dangling bond via ab initio electronic and phononic state calculations. This insight may help advancing graphene device performance through interfacial control.

Original languageEnglish
Article number155431
JournalPhysical Review B
Volume96
Issue number15
DOIs
Publication statusPublished - 2017 Oct 11

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Condensed Matter Physics

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    Minamitani, E., Arafune, R., Frederiksen, T., Suzuki, T., Shahed, S. M. F., Kobayashi, T., Endo, N., Fukidome, H., Watanabe, S., & Komeda, T. (2017). Atomic-scale characterization of the interfacial phonon in graphene/SiC. Physical Review B, 96(15), [155431]. https://doi.org/10.1103/PhysRevB.96.155431