Raman spectroscopy of graphene irradiated with highly charged ions

Graphene is a single layer carbon sheet with a honeycombed lattice. It has attracted widespread research attention because of its distinctive properties. Highly charged ions have high potential energy because they are stripped of many of their bound electrons. In this study, graphene and highly oriented pyrolytic graphite (HOPG) were bombarded with highly charged Xe ions, following which their Raman spectra were measured. The D peak at 1350 cm(-1) appeared in the spectra of both HOPG and graphene, indicating, impact defects. The spectra were fitted to a Lorentzian function, and the parameters of the peaks were obtained. For the Raman spectrum of HOPG irradiated with Xe10+, the peak area ratio of the D peak to the G peak increased linearly with the square root of irradiation fluence. After Xe26+ irradiation, the ratio was saturated with the square root of the fluence. For graphene, the ratio was saturated with Xeq+ bombardment (q = 10, 15, 20, 26), suggesting that a nanostructure formed on the surfaces of both graphene and HOPG. A model was proposed to explain the spectra results. (C) 2016.Elsevier B.V. All rights reserved.