Presentation Information
[1P34]Gas-adsorption effects on Defect-introduced Epitaxial graphene by Ion-beam irradiation
*Taisei Suzuoka1,3, Syogo Mizutani1, Takumi Yoshida1,3, Yuya Miyake2, Kazuyuki Takai1,3 (1. Department of Applied Chemistry, Graduate School of Science and Engineering, Hosei University, Tokyo 184-8584, Japan, 2. Department of Chemical Science and Technology, Hosei University, Tokyo, 184-8584, Japan, 3. Research Center of Ion Beam Technology, Hosei University, Tokyo 184-0002, Japan)
Graphene, composed of carbon atoms in a honeycomb lattice, is attracting attention as a hydrogen storage material, where hydrogen-terminated defects promote the dissociative adsorption of H2 and atomic hydrogen diffusion into the two-dimensional plane. Thermal decomposition of silicon carbide (SiC) above 1000 °C offers a large-scale graphene sample, epitaxial graphene (EG). We investigate the effects of ion beam-induced defects in EG, followed by hydrogen or oxygen exposure. Raman spectra showed that the ratio (ID / IG), which indicates the amount of defects on EG, increased with increasing irradiation time, where H2 exposure to the defects gives a larger ID / IG than O2 due to a more diffusive nature into the EG plane. The Si/C ratio estimated by XPS was larger after O2 exposure than after H2 exposure, because carbon atoms on defect-introduced EG reacted to form CO and CO2, leading to further chemical etching of the graphene.