Facile synthesis of wide-bandgap fluorinated graphene semiconductors

The bandgap opening of graphene is extremely important for the expansion of the applications of graphene-based materials into optoelectronics and photonics. Current methods to open the bandgap of graphene have intrinsic drawbacks including small bandgap openings, the use hazardous/harsh chemical oxidations, and the requirement of expensive chemical-vapor deposition technologies. Herein, an eco-friendly, highly effective, low-cost, and highly scalable synthetic approach is reported for synthesizing wide-bandgap fluorinated graphene (F-graphene or or fluorographene) semiconductors under ambient conditions. In this synthesis, ionic liquids are used as the only chemical to exfoliate commercially available fluorinated graphite into single and few-layer F-graphene. Experimental and theoretical results show that the bandgap of F-graphene is largely dependent on the F coverage and configuration, and thereby can be tuned over a very wide range.