Graphene arch gate SiO₂ shell silicon nanowire core field effect transistors

We report the realization of graphene arch gate silicon nanowire field effect transistors with SiO₂ shell serving as a gate insulator. The arch coverage of the SiO₂ shell was achieved by the flexible graphene layers complying the top of the shell. The wrapping angle was defined by the relative strength of the van der Waals forces on the shell and the substrate. The leakage current of the graphene gate was only 55 fA, while the maximum on-off ratio of 16.7 was obtained. The effective mobility and quantum capacitance of the graphene layers were also obtained from the electronic transport data.