Silver Nanowires/Graphene Oxide Hybrid Transparent Electrode

Presented by Sunghoon Jung, Korea Intitute of Materials Science

Transparent electrodes (TE) are essential for various opto-electronic devices such as touch sensing panels, organic light emitting diodes and thin film solar cells. Recently, flexible electronics has been paid attention for next generation electronic devices. There are rapidly increasing interests about flexible TEs. Typically, hundreds nanometer of indium-tin-oxide (ITO) film has been used as TEs due to its excellent transparency and low electrical resistance. The poor flexibility and high process temperature of ITO, however, are main bottlenecks to apply ITO as transparent electrode of flexible devices [1]. Many researchers have studied various materials which have potentials as flexible transparent electrode such as metal nanowires, metal mesh, graphene and PEDOT:PSS [2-5]. Among the materials, silver nanowire is one of the strong candidates for substitution of ITO on account of comparable electrical and optical properties with high flexibility besides silver nanowire could be formed at room temperature [6]. Even though silver nanowire possess a lot of potentials for flexible devices, one problem of silver nanowire is delamination when silver nanowire is bent. Graphene oxide, functionalized graphene for high solubility in water, has many oxygen containing groups (-COOH, -OH, -CO, etc.), so it can be easily formed on the surface of silver nanowire. Graphene oxide flakes on the surface of silver nanowire build interconnections of nanowires and keep against oxygen and water vapor in the air [7-8].

Herein, we introduce highly conductive and stable silver nanowire and graphene oxide hybrid transparent electrode formed by solution process. We apply mild plasma treatment in order to make the hydrophilic substrate, remove the dispersion agent in silver nanowire and reduce the graphene oxide to reduced graphene oxide. In result, electrical resistance of silver nanowire electrode was decreased by 10% and an environmental stability was improved with over coated graphene oxide.