Laser‐Initiated Covalent Functionalization of Graphene Using Perfluorophenylazides with Local Addend‐Binding Control

This study investigates the laser‐activated covalent functionalization of graphene using methyl‐4‐azidotetrafluorobenzoate (PFPA‐CO 2 Me) as heterobifunctional model compound. By introducing perfluorophenyl azides to the portfolio of suitable precursors, this study achieves a successful, locally controlled covalent functionalization with the attachment of in situ generated singlet aryl nitrene radicals on graphene. Its results indicate that the reaction is likely initiated by a hot electron injection from graphene, acting as a photosensitizer, to the PFPA. Scanning Raman microscopy reveals clear signatures of covalent attachment, demonstrating the tunable control of the degree of functionalization by adjusting laser irradiation parameters. At higher laser powers and prolonged irradiation times, a competing photopolymerization reaction of the highly reactive nitrene intermediates is observed, leading to the formation of disordered carbon and polymeric films, highlighting a key challenge in process control. Kelvin probe force microscopy measurements confirm a tunable drop in surface potential in functionalized regions, directly correlating with the degree of functionalization due to the electron‐withdrawing nature of the attached moieties. This work broadens the scope of laser‐triggered functional moiety attachment to graphene, paving the way for the precise manipulation of its electronic properties and the fabrication of novel, locally controlled heterostructures for electronic applications.