Solution-Processed Copper/Reduced-Graphene-Oxide Core/Shell Nanowire Transparent Conductors

Copper nanowire (Cu NW) based transparent conductors are promising candidates to replace ITO (indium tin-oxide) owing to the high electrical conductivity and low-cost of copper. However, the relatively low performance and poor stability of Cu NWs under ambient conditions limit the practical application of these devices. Here, we report a solution-based approach to wrap graphene oxide (GO) nanosheets on the surface of ultrathin copper nanowires. By mild thermal annealing, GO can be reduced and high quality Cu r-GO core shell NWs can be obtained. High performance transparent conducting films were fabricated with these ultrathin core shell nanowires and excellent optical and electric performance was achieved. The core shell NW structure enables the production of highly stable conducting films (over 200 days stored in air), which have comparable performance to ITO and silver NW thin films (sheet resistance similar to 28 Omega/sq, haze similar to 2% at transmittance of similar to 90%).