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arXiv · 1502.02568

Giant Surface Charge Density of Graphene Resolved From Scanning Tunneling Microscopy and First-Principles Theory

P. Xu·Y. Yang·S. D. Barber·M. L. Ackerman·J. K. Schoelz·I. A. Kornev·S. Barraza-Lopez·L. Bellaiche·P. M. Thibado
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Abstract

In this work, systematic constant-bias, variable-current scanning tunneling microscopy (STM) measurements and STM simulations from density-functional theory are made, yielding critical insights into the spatial structure of electrons in graphene. A foundational comparison is drawn between graphene and graphite, showing the surface charge density of graphene to be 300 percent that of graphite. Furthermore, simulated STM images reveal that high-current STM better resolves graphenes honeycomb bonding structure because of a retraction which occurs in the topmost dangling bond orbitals.

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P. Xu, Y. Yang, S. D. Barber, M. L. Ackerman, J. K. Schoelz, I. A. Kornev, S. Barraza-Lopez, L. Bellaiche, P. M. Thibado. 2015-02-09. Giant Surface Charge Density of Graphene Resolved From Scanning Tunneling Microscopy and First-Principles Theory. https://arxiv.org/abs/1502.02568

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