AVS 64th International Symposium & Exhibition
    Scanning Probe Microscopy Focus Topic Tuesday Sessions
       Session SP+AS+MI+NS+SS-TuM

Paper SP+AS+MI+NS+SS-TuM3
How is Armchair Graphene Nanoribbon Oxidized?

Tuesday, October 31, 2017, 8:40 am, Room 10

Session: Probing Chemical Reactions at the Nanoscale
Presenter: Chuanxu Ma, Oak Ridge National Laboratory
Authors: C. Ma, Oak Ridge National Laboratory
A.A. Puretzky, Oak Ridge National Laboratory
A.P. Baddorf, Oak Ridge National Laboratory
Z. Xiao, North Carolina State University
W. Lu, North Carolina State University
K. Hong, Oak Ridge National Laboratory
J. Bernholc, North Carolina State University
A.-P. Li, Oak Ridge National Laboratory
Correspondent: Click to Email
The stability of graphene nanoribbons (GNRs) in air is crucial for practical applications. Here we study the temperature stability of the armchair GNR with a width of seven carbon atoms (7-aGNR) after exposed to air. Combining scanning tunneling microscopy, Raman spectroscopy, x-ray photoemission spectroscopy, and first-principles theory calculations, the oxidization of the armchair GNRs is found to start from the edges at ab out 520 °C, while below 430 °C the edges are unchanged. Two different types of oxygen species are atomically identified, specifically hydroxyl (OH) and atomic oxygen bridging two carbons, both of which are common oxygen forms in oxidized graphitic lattices. The bandgap is significantly reduced from 2.6 eV to 2.3 eV and 1.9 eV in the vicinity of hydroxyl or bridge O, respectively. Our results suggest that the oxidization will greatly affect the transport properties of GNRs. This research was conducted at the Center for Nanophase Materials Sciences, which is a DOE Office of Science User Facility.