Neutral-pH PEDOT:PSS as over-coating layer for stable silver nanowire flexible transparent conductive films

The silver nanowire (AgNW) mesh film with poly(3,4-ethylenedioxythiophene): poly(styrenesulfonate) (PEDOT:PSS) as the over-coating layer is a promising flexible transparent conductive film technology. In this work, experimental studies show that the hygroscopic and acid properties of the common PEDOT: PSS lead to poor stabilities of the composite films, due to the conductivity degradation of PEDOT: PSS by the water absorption and the acid corrosion of AgNWs by PEDOT: PSS. By using the modified PEDOT: PSS of neutral pH as the over-coating layer, the long term shelf-life time, thermal and current stressing stabilities are all significantly improved without sacrifice of transparency, electrical conductivity and mechanical flexibility. Under both cases of thermal aging test at 210 degrees C for 20 min and 12 h continuous current stressing at a current density of 30 mA/cm(2), no obvious change of the conductivity is observed. The results clearly demonstrate that using the neutral-pH PEDOT: PSS as an over-coating layer can help to achieve flexible AgNW transparent conductive films with superior stability for flexible optoelectronic devices. (C) 2014 Elsevier B.V. All rights reserved.