Investigation on the Silver Nanowire/Graphene Transparent Electrode in Electrochromic Device

In this work, we fabricated a flexible silver nanowires (Ag NWs)/graphene transparent conducting film on polyethylene terephthalate (PET) substrate, which was applied in an electrochromic device. The graphene layer was coated on the surface of the Ag NW film utilizing the electrostatic adsorption in order to improve the stability of the metallic nanowire layer and the performance of the electrochromic device. The Ag NWs/graphene composite film exhibited an optical transmittance of 82.5% at 550 nm and a sheet resistance of 57.5 Ω/sq. With the concentration of the adsorbed graphene increased, the transmittance and conductivity of the composite film both decreased. Furthermore, the lifetime of the electrochromic devices based on the tungsten oxide (WO3) thin film and the Ag NW/graphene composite electrodes was greatly extended, compared to that utilizing the pristine Ag NW electrodes. The results indicate that the introduction of the graphene layer could protect the Ag NW film from corrosion of the electrolyte layer, and greatly improve the lifetime and cycle numbers of the electrochromic device. Key words: silver nanowire; graphene; transparent electrode; electrochromic devices