Vortex-assisted layer-by-layer assembly of silver nanowire thin films for flexible and transparent conductive electrodes

Abstract

Silver nanowires (AgNWs) have drawn much attention as potential candidates to replace conventional transparent conductive materials such as indium tin oxide (ITO). AgNWs have advantages over ITO with respect to cost and ease of fabrication, and can be used in flexible electrodes. However, the preparation of homogeneous films from the AgNW colloidal suspension is still a challenge mainly because of the coagulation and sedimentation of AgNWs in aqueous media. In this study, uniform transparent conductive films were prepared by using AgNWs paired with poly(allylamine hydrochloride) (PAH) via the vortex assisted layer-by-layer (VA-LbL) assembly method. We introduced poly(allylamine hydrochloride) (PAH) to bind the AgNWs to the substrates via coordination bonding. Vortex agitation was also applied during the adsorption of AgNWs to achieve a uniform deposition on the substrate. We systematically examined other experimental conditions such as the concentration of AgNW solution and temperature of the heat treatment to correlate them to the transparency and the conductivity of the films. In addition, AgNW films were prepared on transparent and flexible substrates and these exhibited excellent durability against bending (1000 bending cycles).