Rapid self-assembly of ultrathin graphene oxide film and application to silver nanowire flexible transparent electrodes†
Featuring outstanding electrical and optical properties, silver nanowires (AgNWs) have been regarded as one of the most promising candidates for ITO to manufacture transparent conductive electrodes. However, the poor long-term stability of bare AgNWs, due to sulfidation/oxidation corrosion, is an unavoidable and urgent problem in practical applications. In the present work, a large-area ultrathin and uniform graphene oxide (GO) film was freely self-assembled at the interface of pentane–water by a rapid process within only 3 minutes, and subsequently transferred onto the surface of AgNW film by a simple dip coating process, resulting in an impressive improvement in the conductive performance and stability of the AgNWs. The ultrathin GO film was formed by the evaporation driven instability effect of acetone to induce the self assembly of GO nanosheets and an assistant thermal treatment to accelerate the formation rate. The thickness of GO film could be effectively controlled by changing the amount of acetone and the self-assembly time. The sheet resistance of the GO/AgNW electrode has been decreased approximately 3–4 times, with only a 2% loss in transmittance, compared to the original AgNW electrode. A GO/AgNW electrode with a sheet resistance of 21.5 Ω sq−1 at 90% transmittance has been achieved. The stability of the AgNW electrodes at room temperature and high temperature (120 °C) environments has been improved using GO as a protective film. The uniform and large-scale GO film can be transferred onto various substrates by a simple dip coating method with an arbitrary shape, which will open a new window for the protection of various metal nanowires.