Ultra-stable and high-performing flexible transparent heater using tungsten oxide-covered silver nanowire films embedded in polymer

Abstract

The remarkable conductivity and flexibility of a transparent heater (TH) fabricated using silver nanowires (AgNWs) make it a promising material for flexible electronic applications. However, issues such as oxidation, poor adhesion, and low thermal stability hinder the practical applications. In this work, we fabricate a long-lasting and high-performing conductive, transparent and flexible electrode by coating AgNWs with tungsten oxide (WOx) and embedding within polyimide (PI) matrix. The uniform WOx thin layer coating increases the conductivity of the overall films by reducing the contact resistance and at the same time inhibits the surface oxidation of AgNWs by forming a core-shell structure. PI helps in enhancing their mechanical durability and increase in thermal stability. The transparent electrode obtained by coating AgNWs with tungsten oxide (WOx) and embedding within polyimide (PI) matrix with structure of AgNWs-WOx/PI delivered sheet resistance of 5.3 ± 0.26 Ω/□ with 80% transparency and remains stable after number of bending, peeling, and washing cycles. The TH fabricated from AgNWs-WOx/PI electrode of size 2.5 cm x 3 cm generated an extremely high temperature of 197 oC within 10 s by supplying a power of only 5 V, which remained stable after several repeated cycle test.