Abstract
We present a safe, clean, convenient and easy-to-control method for extensive fluorination of graphene using laser-ablation-assisted decomposition of gaseous SF6 molecules. The decomposition process is based on irradiation of a silicon target using a Nd:YAG laser (532 nm) in an SF6 atmosphere.
The reactive species produced in the plume above the silicon target are consequently responsible for fluorination of graphene placed in proximity to the plume. The applicability of the proposed method is demonstrated on fluorination of CVD-grown graphene on copper foil.
Samples with different fluorination levels were evaluated using both X-ray photoelectron spectroscopy and Raman spectroscopy. The influence of the applied number of laser pulses on the nature of the CeF bonds, fluorine and sulphur concentrations, as well as graphene damage, is discussed.
The method enables control of fluorine content by simple counting of laser pulses. We show that a fluorination level corresponding to a stoichiometry up to C1.4F can be achieved.
The fluorination does not lead to the formation of Cu-F, in contrast to previously published approaches. (c) 2019 Published by Elsevier Ltd.