Flexible and Transparent Composite Electrode of Graphene−Silver nanowires for Quantum-Dot Light-Emitting Diodes

In this work, a flexible and transparent composite electrode of graphene-silver nanowires prepared by spray coating is proposed. The spraying method is easy to operate, low-cost, high-efficiency and can be used to prepare flexible electrodes in a large scale. The sprayed silver nanowires on graphene film can overcome the poor electrical contact behavior of the pristine silver nanowire network due to the high roughness and weak physical contact between the film and the underlying substrate. This results in a conductivity of composite electrode four times that of the silver nanowire film. After 10,000 mechanical bending cycles, the resistance of the silver nanowire film increases about 92%, while the change in the composite electrode is only 4%, indicating a dramatically improved mechanical flexibility. The presence of the graphene film prevents the oxidation of silver nanowires and the failure caused by external forces. The composite electrode demonstrates excellent moisture resistance and their electrical resistance remains stable in a wide humidity condition from 35% to 95% relative humidity. In contrast, the resistance of the pristine silver nanowire film almost doubled because of wetness. Moreover, the composite electrode possesses better light transmission compared to commercial indium tin oxide electrodes. The combined good conductivity and high transmittance show great advantages in flexible display applications and potentiality for replacing the commercialized ITO film.