Local surface potential variations and charge puddling in graphene on SiC(0001)

ORAL

Abstract

We performed Kelvin probe microscopy in ultra-high vacuum on epitaxial graphene grown on SiC(0001). In agreement with previous work, we see discrete surface potentials corresponding to interface layer and monolayer regions separated by steps of $\sim $100 mV. We used the step width to determine the spatial resolution of the probe to be approximately 20 nm. Within a monolayer area we see smaller fluctuations in surface potential of only a few mV. The data set limits on the scale of possible electron/hole puddles in monolayer graphene on SiC(0001).

*This work was supported by the University of Maryland MRSEC.

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Authors

  • A.E. Curtin

    • Materials Research Science and Engineering Center and Center for Nanophysics and Advanced Materials, Department of Physics, University of Maryland

  • W.G. Cullen

    • Materials Research Science and Engineering Center and Center for Nanophysics and Advanced Materials, Department of Physics, University of Maryland

  • Michael Fuhrer

    • University of Maryland
    • Center for Nanophysics and Advanced Materials, University of Maryland, College Park, MD 20742-4111, USA
    • Center for Nanophysics and Advanced Materials, University of Maryland, College Park
    • Center for Nanophysics and Advanced Materials, Univesity of Maryland
    • Materials Research Science and Engineering Center and Center for Nanophysics and Advanced Materials, Department of Physics, University of Maryland
    • Dept. of Physics, Materials Research Science and Engineering Center and Center for Nanophysics and Advanced Materials, Univ. of Maryland, College Park

  • R.L. Myers-Ward

    • U.S. Naval Research Laboratory, Code 6800, Washington, DC 20375

  • L.O. Nyakiti

    • U.S. Naval Research Laboratory, Code 6800, Washington, DC 20375

  • V.D. Wheeler

    • U.S. Naval Research Laboratory, Code 6800, Washington, DC 20375

  • D.K. Gaskill

    • U.S. Naval Research Laboratory, Code 6800, Washington, DC 20375