Ion irradiation of supported graphene : Defect formation and atmospheric doping

Abstract

In this paper, we study structural and adsorption properties of graphene irradiated with 46 MeV Ar ions and 240 keV H ions on SiO2/Si and copper substrates by micro-Raman spectroscopy. Graphene irradiated with H ions demonstrated evidence of both high and low defect density regions on a sub-micron scale. TRIM calculations showed that substrate was the dominant defect source with a contribution from about 55% for H ions in graphene on SiO2/Si to 90% for Ar in graphene on SiO2/Si. Charge carrier density analysis showed p-type adsorption doping saturating at (0.48 ± 0.08) × 1013 cm−2 or (0.45 ± 0.09) × 1013 cm−2 with a defect density of 1.5 × 1011 cm−2 or 1.2 × 1011 cm−2 for graphene on SiO2/Si or copper, respectively; this was analyzed in the framework of physisorption and dissociative chemisorption. This study is useful towards the development of functionalization methods, molecular sensor design, and any graphene application requiring modification of this material by controlled defect introduction.