One-step aqueous fabrication of silver nanowire composite transparent conductive film with high uniformity and stability
Sliver nanowire (AgNW) network has been a promising candidate for transparent conductive film (TCF), but the introduction of top protection layer via two-step method is generally required to improve the stability, adhesion and roughness. And the organic solvent in diluted AgNW coating solution has been causing serious hazard problem during its evaporation to open air. In this study, one-step solution process based on water dispersed hybrid ink was developed to fabricate composite TCFs with comparable performance. It significantly simplified the fabrication process, and minimized the chemical hazard. An optimized ratio of chitosan-lactic acid (Chi-LaA) was introduced to AgNW aqueous dispersion to fabricate the composite TCF with good film coating capability and improved stability. A coefficient of variation less than 0.1 was found for the composite TCF, which is dominating the pristine one that prepared with aqueous dispersion as well, whose up to 0.49. As a result, the Chi-LaA/AgNW (0.2:1) TCF exhibits enhanced stability, adhesion, and surface flatness. It showed only 33% of increase in sheet resistance after 300 days in ambient environment and illustrated 6.6 times the lifetime of pristine AgNW TCF under 250 mA cm-2 of current stress. It sustained 100 times of tape adhesion tests and 13 h of solvent ultrasonic vibration without significant change in conductivity. Film heaters has been made with the Chi-LaA/AgNW composite TCFs achieving uniform and stable temperature of ~135 °C at a low voltage of 6 V with fast heating rate, good repeatability and long lifetime.