AVS 64th International Symposium & Exhibition
    2D Materials Focus Topic Tuesday Sessions
       Session 2D+AS+SA+SP-TuM

Paper 2D+AS+SA+SP-TuM5
Spectroscopic Investigation of Plasma-Fluorinated Monolayer Graphene and Application for Gas Sensing

Tuesday, October 31, 2017, 9:20 am, Room 15

Session: 2D Materials Characterization including Microscopy and Spectroscopy
Presenter: Hui Zhang, Shanghai Institute of Microsystem And Information Technology, China
Authors: H. Zhang, Shanghai Institute of Microsystem And Information Technology, China
J.-H. Guo, Lawrence Berkeley National Laboratory
X. Sun, Soochow University
Correspondent: Click to Email
A large-area monolayer fluorinated graphene (FG) is synthesized by a controllable SF6 plasma treatment. The functional groups of FG are elucidated by various spectroscopies, including Raman, X-ray photoemission spectroscopy (XPS) and near edge X-ray absorption fine structure (NEXAFS). Raman results suggest that the defects are introduced into the monolayer graphene during the fluorination process. The fluorine content can be varied by the plasma treatment and can reach the maximum (~24.6 at% F) under 20 s plasma treatment as examined by XPS measurement. The angle dependent NEXAFS reveals that the fluorine atoms interact with the graphene matrix to form the covalent C-F bonds, which are perpendicular to the basal plane of FG. FG is applied as gas sensing material and owns much better performance for ammonia detection compared to the pristine graphene. Based on our DFT simulation results, the fast response/recovery behavior and high sensitivity of the FG gas sensor are attributed to enhanced physical absorption due to the C-F covalent bonds on the surface of FG