Copper/silver nanoparticle incorporated graphene films prepared by a low-temperature solution method for transparent conductive electrodes

A facile one-step co-reduction and low-temperature solution process was developed to prepare Cu–graphene (Cu–G), Ag–graphene (Ag–G), and Cu–Ag–graphene (Cu–Ag–G) composite films on glass substrates. Scanning electron microscope and transmission electron microscope images show that Cu/Ag nanoparticles are either distributed on the surface of graphene nanosheets or covered by graphene. The conductivity and transparency of these films were studied, and the results show that incorporation of Cu and Ag nanoparticles into graphene films can improve film conductivity. Ag nanoparticles are more effective in improving film conductivity. The conductivity and transparency of the composite films can be balanced by introducing the optimum amount of Cu or Ag nanoparticles. The conductivity and transparency of Cu–Ag–G films with optimum metal nanoparticle concentration are as good as those of Ag–G composite films. The Cu–Ag–G films meet the requirements of low-cost, high-conductivity, and transparent films that can be used as electrode materials. Thus, the proposed low-temperature solution process is a new route to preparing low-cost transparent and conductive electrodes on various substrates, including glass and flexible polymer substrates.