Atomic Force Microscopy-Based Local Tunable Oxidation of Graphene

We have fabricated graphene/graphene oxide/graphene (G/GO/G) junctions by local anodic oxidation lithography using atomic force microscopy (AFM). The conductance of the G/GO/G junction decreased with the bias voltage applied to the AFM cantilever $V_{tip}$. For G/GO/G junctions fabricated with large and small $\vert V_{tip}\vert $. GO was semi-insulating and semiconducting, respectively. AFM-based LAO lithography can be used to locally oxidize graphene with various oxidation levels and achieve tunability from semiconducting to semi-insulating GO [S. Masubuchi \textit{et al.}, Nano Lett. \textbf{11}, 4542 (2011).]