Improvement of Conductivity and Adhesion of AgNW Flexible Transparent Conductive Coatings by the Capillary Forces Effect and Polyvinyl Alcohol

Silver nanowires (AgNW) are prospective for the fabrication of flexible transparent conductive coatings. The main challenge is to ensure low sheet resistance of AgNW coatings at flexible substrates. Herein, a simple low-temperature post-treatment method is proposed for improving the conductivity and adhesion of AgNW coatings which is based on the deposition of distilled water (DI) with a small amount of dissolved polyvinyl alcohol (PVA). Capillary forces cause a decrease in the sheet resistance of AgNW coatings while the presence of PVA significantly improves the adhesion of nanowires to the flexible polyethylene terephthalate (PET) substrates. As a result, coatings with a transparency of 91% and a sheet resistance of 20 Ω sq^‒1 are fabricated. The storage time of coatings in air is increased due to the presence of a thin layer of PVA on AgNW. After 90 days, the sheet resistance of post-treated AgNW coatings is increased by 11 times, while the sheet resistance of untreated coatings is increased by more than 3000 times. The obtained AgNW coatings are utilized as flexible transparent heaters.