AVS 59th Annual International Symposium and Exhibition
    Electron Transport at the Nanoscale Focus Topic Thursday Sessions
       Session ET+SS+GR+SP-ThA

Paper ET+SS+GR+SP-ThA6
Electron Transport Study of Graphene Grain Boundaries Using Scanning Tunneling Potentiometry

Thursday, November 1, 2012, 3:40 pm, Room 16

Session: Electron Transport at the Nanoscale: Molecules and Defects
Presenter: K. Clark, Oak Ridge National Laboratory
Authors: K. Clark, Oak Ridge National Laboratory
X.-G. Zhang, Oak Ridge National Laboratory
I. Vlassiouk, Oak Ridge National Laboratory
A.-P. Li, Oak Ridge National Laboratory
Correspondent: Click to Email
Graphene, due to its unique electronic structures, has quickly become one of the most notable “super-materials” poised to transform the electronics and nanotechnology landscape. The symmetry of the graphene honeycomb lattice is a key element for determining many of graphene’s unique electronic properties, such as the linear energy-momentum dispersion and the reduced backscattering (i.e., high carrier mobility). However, topological lattice defects, such as grain boundaries and step edges, break the sublattice symmetry and can affect the electronic properties, especially in transport of graphene in unexpected ways. To utilize the full potential of graphene a complete understanding of the physical and electronic properties of defects in this system is needed. By using a scanning tunneling potentiometry method with a low temperature four-probe scanning tunneling microscope, two-dimensional maps of electrochemical potentials have been measured across individual grain boundaries on the graphene films grown on copper foil and transferred to SiO2. An Atomic Force Microscope (AFM) is implemented to image the grain boundary that forms between individual graphene flakes that grow on the surface. The AFM imaging along with scanning tunneling potentiometry characterize the grain boundaries formed between coalesced grains on the SiO2 surface. Results of the influence of the grain boundary on the electronic transport across 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.