AVS 58th Annual International Symposium and Exhibition
    Graphene and Related Materials Focus Topic Wednesday Sessions
       Session GR-WeA

Paper GR-WeA11
Hydrogenation of Epitaxial Graphene on 6H-SiC(0001): The Formation of Hydrogen-Vacancy Complex

Wednesday, November 2, 2011, 5:20 pm, Room 208

Session: Graphene Characterization including Microscopy and Spectroscopy
Presenter: Lian Li, University of Wisconsin-Milwaukee
Authors: Y. Liu, University of Wisconsin-Milwaukee
M. Weinert, University of Wisconsin-Milwaukee
L. Li, University of Wisconsin-Milwaukee
Correspondent: Click to Email
In this work, we have studied the hydrogenation of epitaxial graphene on 6H-SiC(0001) by Ar/H2 plasma at room temperature. Two predominant types of defects are observed, and their atomic and electronic structures are studied by scanning tunneling microscopy/spectroscopy (STM/STS) and first principles calculations. The results suggest that vacancies are created with hydrogen atoms trapped nearby between the graphene sheets, forming H-vacancy complexes. In addition, changes in the electronic structures of the defects are also observed during STM imaging, which can be attributed to the dissociation and recombination of these complexes by the electric field of the STM tip. These results and their impact on the gap opening in hydrogenated graphene will be presented at the meeting.