Fabrication of Transparent and Conductive Graphene Film from Graphite by Using Non-Ionic Polymer Surfactant

Abstract

Graphene, a new material with 2-dimensional nanostructure consisting of a single layer of sp2 network of carbon atoms, has distinctive electronic properties such as room temperature quantum effects, arnbipolar electric field effects, and high carrier mobility. It is, however, difficult to fabricate graphene film from graphite via a solution process using organic solvent, though it is a cheap and convenient way compared to the CVD method. In this study, we report a new method to fabricate graphene film using a polymer surfactant to disperse homogeneously graphene sheets in ethanol. The surfactant consists of oligothiophene, which is strongly adsorbed onto the graphene surface, and polyethylene glycol, which interacts with ethanol. Hence, the surfactant is expected to effectively disperse graphene sheets in ethanol. Graphene film with a sheet resistance of 300 0/sq at 72% transmittance at 550 nrn was fabricated by vacuum filtration. When the film quality and thickness of graphene sheets are measured by Raman spectroscopy and transmission electron microscope, it reveals that our films have better quality as compared to graphene films reported previously.