Layer engineering of graphene with oxygen plasma etching

A simple and controllable method was developed to engineer the layer number of graphene based on oxygen plasma etching technique. With the optimum parameters, our so-called “one layer etching” process can be used to remove one single graphene layer at a time. As experimental demonstrations, mono-layer graphenes gotten from bi-layer graphenes and the one layer peeling of a few-layer graphene gotten from a graphite flake (~20 nm thick) were presented in this paper. This technique will open up new possibilities for making graphenes with higher efficiency than that of the commonly used mechanical exfoliation method.