Highly conductive silver nanowire transparent electrode by selective welding for organic light emitting diode

A highly smooth, conductive and air-stable flexible transparent silver nanowire (AgNW) composite film is developed by solution process without high temperature treatment. The sheet resistance of the AgNW/polyvinyl butyral (PVB) film decreases significantly after the film is immersed into the silver-ammonia and glucose mixed solution for only a few seconds. The solution selectively wets the AgNWs rather than the PVB substrate, because the AgNWs is hydrophilic while the PVB is hydrophobic. The silver-ammonia on the surface of the AgNWs is reduced into silver, which solders the nanowire assembles together. This selective welding of the AgNWs greatly increases the electrical conductivity of the composite film without obviously attenuating its transmittance. Specifically, the sheet resistance of this AgNW composite film is 10.1 Ω/sq with a transmittance of 87% at the wavelength of 550 nm, and it also shows excellent stability. The film can be easily patterned and employing this composite film as an anode, the organic light emitting diode exhibits comparable performance to the ITO device. This simple and effective solution process method shows strong potential to be applied in industrial mass production.