<i>In Situ</i> Transport Measurements and Band Gap Formation of Fluorinated Graphene

Abstract

Electrical transport properties were studied in situ of few layer graphene subjected to plasma-induced sequential fluorination processes. Low-temperature transport properties and Raman spectroscopy were studied ex situ after each fluorination process. As the fluorination progresses, it was found that the initial metallic behavior of graphene (with low-temperature transport properties being governed by diffusion) changes to insulating behavior where transport properties obey variable range hopping (VRH). Emergence of pronounced negative magnetoresistance (MR) for strongly fluorinated graphene was also observed. As determined by the high-temperature resistance behavior, an emergence of a small band gap is observed and the band gap is seen to increase as the fluorination progresses.