Engineering the Persistent Optical Gating Effect of 2D Materials on SrTiO3

ORAL

Abstract

Reducing the dimensionality of bulk materials to atomically thin films allows for exploration of novel phases. The carrier density often plays a crucial role in accessing these phases. Using a persistent all-optical gating effect, local control over the carrier density in graphene, MoS2, phosphorene, and a thin layer of (Bi,Sb)2Te3 on SrTiO3 substrates has been recently demonstrated [1,2,3]. The effect is postulated to originate from a reversible optically modulated space-charge region in the SrTiO3, though exact details of the mechanism, such as the role of various defects and its relation to other optically induced persistent phenomena, have remained unclear. Using Kelvin probe microscopy, conductivity measurements, and optical transmission spectroscopy of graphene on SrTiO3, combined with density-functional calculations, we address outstanding questions on the role of defects, and provide ways to engineer and enhance the effect.

[1] A. L. Yeats et al., Sci. Adv. 1, e1500640 (2015)
[2] E. C. Vincent et al., in prep (2017)
[3] F. Liu et al., Adv. Mat. 28, 7768 (2016)

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Presenters

  • Joost van Bree

    Institute for Molecular Engineering, University of Chicago

Authors

  • Joost van Bree

    Institute for Molecular Engineering, University of Chicago

  • Erzsebet Vincent

    Institute for Molecular Engineering, University of Chicago

  • Andrew Yeats

    Institute for Molecular Engineering, University of Chicago

  • Meng Ye

    Univ of Chicago, Institute for Molecular Engineering, University of Chicago

  • Giulia Galli

    Institute for Molecular Engineering, University of Chicago, Univ of Chicago, University of Chicago, Institute for Molecular Engineering, University of Chicago; Argonne National Laboratory, Institute for Molecular Engineering, University of Chicago, Chicago, IL, United States and Materials Science Division, Argonne National Laboratory, University of Chicago; Argonne National Laboratory, Institute for Molecular Engineering, Univ of Chicago

  • David Awschalom

    Univ of Chicago, Institute for Molecular Engineering, University of Chicago, University of Chicago