LAUSR

The formation of nanopores by highly charged ion impacts on freestanding fluorine-functionalized graphene is demonstrated. The process is driven by potential sputtering, which becomes active by changing the semimetallic property of graphene into a strongly insulating state by fluorination. The interaction of fluorographene with highly charged ions is also studied in terms of charge exchange and kinetic energy loss. A higher number of captured electrons and a larger kinetic energy loss than in pristine graphene are observed, which can be well explained by an increase in the ion neutralization length and in the atomic areal density of the target, respectively. Using a computer code based on a time-dependent scattering potential model, a connection between the efficiency of charge exchange and the fluorine coverage is revealed. Our results suggest a competition of two distinct nanostructure formation processes, leading either to pore formation or fluorine desorption.