Reversible Hydrogenation and Bandgap Opening of Graphene and Graphite Surfaces Probed by Scanning Tunneling Spectroscopy

Authors

  • Andres Castellanos-Gomez,

    Corresponding author
    1. Physics of Nanodevices, Zernike Institute for Advanced Materials, University of Groningen, The Netherlands
    2. Departamento de Física de la Materia Condensada (C–III), Universidad Autónoma de Madrid, Campus de Cantoblanco, 28049 Madrid, Spain
    Current affiliation:
    1. Kavli Institute of Nanoscience, Delft University of Technology, Lorentzweg 1, 2628 CJ Delft, The Netherlands
    • Physics of Nanodevices, Zernike Institute for Advanced Materials, University of Groningen, The Netherlands.
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  • Magdalena Wojtaszek,

    1. Physics of Nanodevices, Zernike Institute for Advanced Materials, University of Groningen, The Netherlands
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  • Arramel,

    1. Physics of Nanodevices, Zernike Institute for Advanced Materials, University of Groningen, The Netherlands
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  • Nikolaos Tombros,

    1. Physics of Nanodevices, Zernike Institute for Advanced Materials, University of Groningen, The Netherlands
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  • Bart J. van Wees

    Corresponding author
    1. Physics of Nanodevices, Zernike Institute for Advanced Materials, University of Groningen, The Netherlands
    • Physics of Nanodevices, Zernike Institute for Advanced Materials, University of Groningen, The Netherlands.
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Abstract

The effects of hydrogenation on the topography and electronic properties of graphene and graphite surfaces are studied by scanning tunneling microscopy and spectroscopy. The surfaces are chemically modified using an Ar/H2 plasma. By analyzing thousands of scanning tunneling spectroscopy measurements it is determined that the hydrogen chemisorption on the surface of graphite/graphene opens on average an energy bandgap of 0.4 eV around the Fermi level. Although the plasma treatment modifies the surface topography in an irreversible way, the change in the electronic properties can be reversed by moderate thermal annealing and the samples can be hydrogenated again to yield a similar, but slightly reduced, semiconducting behavior after the second hydrogenation.

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