Fast and simple fabrication of a large transparent chemically-converted graphene film by spray-coating

We report the fast, low-cost, simple fabrication of a large chemically-converted graphene (CCG) films by spray deposition of graphene oxide (GO)-hydrazine dispersions. The GO-hydrazine dispersion was prepared by mixing GO dispersion with excess amount of hydrazine monohydrate. By spray deposition on preheated substrate, the creation of the thin film and the reduction of GO to CCG were carried out simultaneously. The prepared CCG films had a low sheet resistance of 2.2 x 10(3) Omega square(-1) and a high transmittance of 84% at a wavelength of 550 nm. Atomic force microscope images clearly showed continuous films resulting from the overlap of graphene sheets and a uniform surface morphology with root mean square about 1 nm. (C) 2010 Elsevier Ltd. All rights reserved.