Silver nanowire network for flexible transparent electrodes based on spray coating at a low DC electric field and plasma treatment

Abstract

Flexible transparent electrodes have been fabricated successfully by using a metal nanowire network. Despite its higher conductivity and transparency, raw silver nanowire (AgNW) film suffers from the random arrangement and high surface roughness originating from the overlaps of a few tens of nanometer-thick AgNWs. In this work, a facile and environmentally friendly method is developed to form AgNW flexible transparent electrodes by spray coating at a low DC electric field (less than 6.0 V) and subsequent plasma treatment. The DC voltage, plasma power, and plasma treatment time of the AgNW network are optimized. The obtained electrodes fabricated by this technique exhibited excellent flexible, transparent, and flat junctions of AgNWs with a sheet resistance of 4.64 Ω · sq−1 and a specular transmittance of 87.3% at a wavelength of 550 nm. Furthermore, the AgNW electrodes are very flexible, highly durable, and moiré-free. The resistance remains almost unchanged over 500 cycles of mechanical deformation with a bending distance of 14 mm when its size is 20 × 20 mm. The as-prepared AgNW electrodes exhibited a root mean square roughness below 13.07 nm at a scan size of 5 × 5 μm. We propose that the improved properties can be attributed to the well-arranged AgNW network acheived by applying a DC electric field and a flat connection between the AgNW junctions induced by plasma treatment.