Highly Conductive and Uniform Alginate/Silver Nanowire Composite Transparent Electrode by Room Temperature Solution Processing for Organic Light Emitting Diode

A novel transparent electrode composed of alginate/silver nanowire (AgNW) with high conductivity and low roughness is fabricated via a solution process at room temperature. The sol–gel transition of the alginate triggered by CaCl 2 solution bonds the AgNWs to the substrate tightly. Meanwhile, Cl – in the solution can renovate the cracks on the AgNW surfaces created during the mechanical pressing, resulting in a great increase of the electrical conductivity. The alginate/AgNW composite film can reach a sheet resistance of 2.3 Ω/sq with a transmittance of 83% at 550 nm. The conductivity of the composite film remains stable after bending and tape tests, demonstrating excellent flexibility and great adhesion of AgNWs to the substrate. Moreover, the composite film shows better stability to resist longtime storage than conventional annealed-AgNW film. The organic light emitting diode using such alginate/AgNW composite film as anode presents current densities and luminances comparable to those of indium tin oxide (ITO) anode, and higher efficiencies are obtained due to the better charge balance.