Rapid and facile fabrication of conducting monolayer reduced graphene oxide films by methane plasma-assisted reduction

In this research article, we report a method to fabricate conducting reduced graphene oxide (rGO) monolayer films reduced by methane plasma treatment within few minutes and the nanoscale characterization of local conductivity via conductive atomic force microscopy (C-AFM), realizing their applicability in highly transparent conducting electrodes. Continuous monolayer graphene oxide (GO) films were fabricated by a simple spin-coating method and reduction of oxygen-containing groups with simultaneous lattice defect restoration was done by methane plasma treatment. Current images obtained by C-AFM provide detailed information about the conductivity through the flakes depending on the plasma irradiation time. Moreover, lattice defect restoration was confirmed by the appearance of the G'-band in Raman spectra, which is in correlation with current images, whereas no G'-band or current image was observed in vacuum annealed samples at similar durations in the absence of methane. This rapid and facile method offers a way to fabricate conductive monolayer rGO films by a short-term plasma treatment allowing to utilize low melting point substrates to form flexible conductive graphene-based films.