Electrical and optical properties of hybrid transparent electrodes that use metal grids and graphene films

There have been efforts to develop alternative transparent conductors to replace indium tin oxide (ITO). A hybrid transparent conductor that integrates a metallic Cu grid and graphene film promises to be a suitable candidate. Flexibility, sheet resistance, and transmittance comparable to ITO have been demonstrated. Here, we show that the optical and electrical properties of the hybrid transparent conductor can be easily tuned by clever design of the metal grid. The outcome of our study provides unprecedented guidelines for future design of metal grids integrated in transparent conductors. We also find that the graphene film forms an effective barrier to retard the degradation of the copper grid when the hybrid transparent conductor is heated in air up to high temperatures for an extended period of time. Hence, a superior hybrid transparent conductor, which can be carefully engineered to display desirable properties, has been demonstrated.