Scanning tunneling microscopy and spectroscopy of wet chemically synthesized porous graphene nanoribbons

ORAL

Abstract

The bottom-up wet chemical synthesis of graphene nanoribbons (GNRs) opens interesting opportunities for tailoring the GNR structure with atomic precision [1]. Atomically precise porous GNRs are a new chemically synthesized variation for which the fabrication procedure yielding multiple pores in a single ribbon and the electronic details of the ribbon have not been reported. In this work, porous GNRs are dry contact transferred in ultrahigh vacuum to clean silicon and III-V semiconducting substrates and examined using UHV scanning tunneling microscopy (STM) and spectroscopy (STS). STM imaging confirms the expected porous structure and indicates a unique electronic feature at the graphene nanopores, and STS measurements indicate a 2.0 eV bandgap. These results are compared to first-principles DFT simulations in which an increased local density of states at the pores is predicted. A GW correction predicts a 3.24 eV bandgap. Illumination of pore effects enables tunability of GNR electronic properties.

[1] Vo, T. H., Shekhirev, M, Kunkel, D. A., Morton, M. D., Berglund, E., Kong, L., Wilson, P. M., Dowben, P. A., Enders, A., and Sinitskii, A., Nat. Commun. 2014, 5, 3189.

*This work was funded by the Office of Naval Research under Grant N00014-16-1-3151.

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Presenters

  • Kaitlyn Parsons

    • Electrical and Computer Engineering, University of Illinois at Urbana-Champaign

Authors

  • Kaitlyn Parsons

    • Electrical and Computer Engineering, University of Illinois at Urbana-Champaign

  • Adrian Radocea

    • Materials Science and Engineering, University of Illinois at Urbana-Champaign

  • Mohammad Pour

    • Chemistry, University of Nebraska-Lincoln

  • Tao Sun

    • Mechanical Science and Engineering, University of Illinois at Urbana-Champaign

  • Alexander Sinitskii

    • Department of Chemistry, University of Nebraska-Lincoln, Lincoln, NE 68588-0304
    • Chemistry, University of Nebraska-Lincoln
    • Chemistry, University of Nebraska - Lincoln

  • N. R. Aluru

    • Mechanical Science and Engineering, University of Illinois at Urbana-Champaign
    • University of Illinois at Urbana-Champaign
    • Department of Mechanical Science and Engineering, University of Illinois at Urbana-Champaign, IL, USA

  • Joseph W Lyding

    • Electrical and Computer Engineering, University of Illinois at Urbana-Champaign
    • University of Illinois at Urbana-Champaign