Role of defect states in functionalized graphene photodetectors

Abstract

The functionalization of graphene can enhance the optoelectronic properties of graphene, allowing the creation of highly sensitive broadband photodetectors. Presently, the role played by defects, induced by the functionalization of graphene, on the performance of graphene photodetectors is not well understood. Here, we investigate the optoelectronic properties of van der Waals heterostructures comprising of graphene and a functionalized partner, formed by pristine and fluorinated graphene. We find that the electrical properties of graphene are preserved upon formation of the heterostructure. A negligible charge transfer is observed across the interface between the two materials which limits the performance of the photodetector due to the vertical separation of the two materials.