title: Spatial fluctuations in barrier height at the graphene-silicon carbide Schottky junction.
abstract: When graphene is interfaced with a semiconductor, a Schottky contact forms with rectifying properties. Graphene, however, is also susceptible to the formation of ripples upon making contact with another material. Here we report intrinsic ripple- and electric field-induced effects at the graphene semiconductor Schottky junction, by comparing chemical vapour-deposited graphene transferred on semiconductor surfaces of opposite polarization-the hydrogen-terminated silicon and carbon faces of hexagonal silicon carbide. Using scanning tunnelling microscopy/spectroscopy and first-principles calculations, we show the formation of a narrow Schottky dipole barrier approximately 10 Å wide, which facilitates the observed effective electric field control of the Schottky barrier height. We further find atomic-scale spatial fluctuations in the Schottky barrier that directly follow the undulation of ripples on both graphene-silicon carbide junctions. These findings reveal fundamental properties of the graphene/semiconductor Schottky junction-a key component of vertical graphene devices that offer functionalities unattainable in planar device architecture.
authors.affiliation: Department of Physics, University of Wisconsin, Milwaukee, Wisconsin 53211, USA.
authors.forename: S
authors.initials: S
authors.lastname: Rajput
authors.forename: M X
authors.initials: MX
authors.lastname: Chen
authors.forename: Y
authors.initials: Y
authors.lastname: Liu
authors.forename: Y Y
authors.initials: YY
authors.lastname: Li
authors.forename: M
authors.initials: M
authors.lastname: Weinert
authors.forename: L
authors.initials: L
authors.lastname: Li