Isotope Engineered Fluorinated Single and Bilayer Graphene

We attempt to stabilize the fluorinated graphene layers in a two-step fluorination process, where, in the first step, we fluorinate single-layer graphene, and subsequently, we transfer an as-grown layer on it to form a fluorinated bilayer. The in situ Raman measurement demonstrates high thermal stability of fluorine in F-BLG. The result was confirmed by a series of characterization techniques, including X-ray photoelectron spectroscopy (XPS), secondary ion mass spectrometry (SIMS), Kelvin probe force microscopy (KPFM) and AFM. Interestingly, the fluorinated bilayer show enhanced light–matter interaction, which has been utilized in proof-of-concept field-effect phototransistors that show high photoresponse in <200 µs. Additionally, with the isotope mass (¹²C and ¹³C) sensitivity, we are able to address several not-yet-understood puzzles in partially fluorinated mono- and bi-layer graphene, such as fluorination sites and directionality. Thus, our study demonstrates new tools for analyzing, understanding, and practical utilization of fluorinated graphene systems. Thus, the study (link) paves a new avenue for the in-depth understanding and practical utilization of fluorinated graphenic carbon.