(405b) Local Curvature Enables Spatially-Defined Properties in Graphene

Selectively functionalized graphene can realize spatially-defined properties that are highly desirable for atom-thin devices. Because curvature tunes the reactivity of graphene, patterning graphene into regions of different local curvatures can achieve domains with different levels of functionalization. Previous buckling methods were limited by the range of tunability over curvature and control of the orientation at the microscale. This presentation describes a scalable approach to achieve spatially selective graphene fluorination using multiscale wrinkles. Graphene wrinkles were formed by relieving the strain in thermoplastic polystyrene substrates conformally coated with fluoropolymer and graphene skin layers. Chemical reactivity of a fluorination process could be tuned by changing the local curvature of the graphene nanostructures. Patterned areas of graphene nanowrinkles and crumples followed by a single-process plasma reaction resulted in graphene having different fluorination levels side-by-side. Because the reduction in conductivity scales with the degree of fluorination, the conductivity of the graphene can now be controlled as a function of feature size.