Fluorinated Graphene

Using a fluoropolymer and a laser beam, researchers have devised a method for fluorinating selected regions of graphene (Nano Lett., DOI: 10.1021/nl300346j). Fluorination breaks up graphene’s conductive electron network, so the new method could isolate conducting regions of graphene—a capability that would be useful for building graphene-based electronic devices, says Rodney S. Ruoff of the University of Texas, Austin, who spearheaded the research. Ruoff’s team layered a fluoropolymer called Cytop over graphene and then irradiated it using a focused laser. This process produces fluorine radicals that react with the underlying graphene. Fluorination is observed only in areas struck by the laser. Although the fluorinated regions have a much higher electrical resistance than pristine graphene, the basic skeletal carbon network of the material remains intact. The researchers report that C–F bond formation can be improved by boosting the laser’s power and by increasing the fluoropolymer’s thickness. Because the electrical isolation via fluorination takes place in one step, the researchers point out that the process would be less expensive than complicated patterning techniques such as photolithography, etching, and liftoff.