AVS 58th Annual International Symposium and Exhibition
    Electron Transport in Low Dimensional Materials Focus Topic Tuesday Sessions
       Session ET+EM+NS+GR-TuM

Paper ET+EM+NS+GR-TuM1
Electron Transport Study of Graphene on SiC Using Scanning Tunneling Potentiometry

Tuesday, November 1, 2011, 8:00 am, Room 209

Session: Electron Behaviors in Nanoelectronics, Interconnect, and Carbon-based Materials
Presenter: Kendal Clark, Oak Ridge National Laboratory
Authors: K. Clark, Oak Ridge National Laboratory
S. Qin, Oak Ridge National Laboratory
G. He, Carnegie Mellon University
G. Gu, The University of Tennessee
R.M. Feenstra, Carnegie Mellon University
A.-P. Li, Oak Ridge National Laboratory
Correspondent: Click to Email
The unique electronic and transport properties of graphene have helped this material emerge as a perspective graphene based electronic system. Single layers of graphene formed on SiC look to be a promising system for the realization of graphene electronics. To utilize the full potential of graphene on SiC a complete understanding of the physical and electronic properties of this system is needed. This study uses Scanning Tunneling Microscope (STM) images along with scanning tunneling spectroscopy to characterize the sample surface. STM images clearly show the distinction between 1 monolayer (ML) and 2ML regions. The 1ML to 2ML transition is further confirmed by point spectroscopy measurements and spectroscopic mapping across the boundary. Defects, grain boundaries, step edges and other potential scattering centers are thought to play a major role in the electronic properties, especially in transport, along the graphene sheets. Using a low temperature four-probe scanning tunneling microscope, potentiometry measurements are performed on epitaxial graphene grown on 4H-SiC. Potentiometry maps spanning the transition from 1ML to 2ML graphene layers show a contrast change indicating a potential change at this interface. Preliminary results of the transport along this potentially revolutionary new electronic system will be presented. This research was conducted at the Center for Nanophase Materials Sciences, which is sponsored at Oak Ridge National Laboratory by the Office of Basic Energy Sciences, U.S. Department of Energy.