Graphene-Based Film Reduced by a Chemical and Thermal Synergy Method as a Transparent Conductive Electrode

Solution-processed graphene oxide (GO) films have tremendous potential in the applications of transparent electrodes. The mechanism of how the GO film is reduced by reducing gas has not been clarified because the reducing gas cannot permeate through the plane of GO. Here, an effective chemical and thermal synergy reduction of GO film was investigated. We also revealed how the reducing gas permeates through the GO film barrier. The GO film was chemically reduced by the vapor of hydriodic acid and acetic acid (HI–AcOH, volume ratio of 1:1) at 100 °C for 3 h, followed by annealing at 1100 °C for 0.5 h in an Ar atmosphere. The reduced graphene oxide (RGO) film had a sheet resistance of 562 Ω/〈 and a transparency of 63.7% at a typical wavelength of 550 nm, which is sufficient for many applications in optoelectronics, and this effective synergy reduction method advances the research on graphene-based electrodes.