Formation of monolayer graphene on a basal HOPG surface irradiated with Xe ions

Highly charged Xeq+ (q = 5, 21, 26) ions with kinetic energy of 450 keV were extracted from electron cyclotron resonance ion source. Highly oriented pyrolytic graphite (HOPG) basal surfaces were impacted by the Xeq+ ions. The samples were analyzed with Raman spectroscopy. There appeared a tiny peak in Raman spectrum at position of 2643 cm−1 for the impact of Xe5+ ion, which suggested the monolayer graphene was formed on the HOPG surface. The intensity of the peak depended on the charge state of incident ions.