Polyimide impregnated silver nanowire-titanium oxide core–shell nanostructures as ultra-stable flexible transparent electrode for multiple applications

Abstract

Silver nanowires (AgNWs)-based flexible-transparent conducting electrode (f-TCE) have various optoelectronic applications. Although, bare AgNW-based f-TCE faces challenges of poor adhesion with the substrate, rough surface and low thermal stability. In this work, we demonstrate preparation of f-TCE by coating a very thin layer of TiO over AgNWs to form AgNW-TiO core–shell structures. Due to very thin TiO film in core–shell structure, the amorphous TiO converted into crystalline and delivered excellent conductivity at low curing temperature of 100 °C. The adhesion and roughness issues are solved by impregnating the core–shell AgNW-TiO within polyimide (PI) matrix. The PI impregnated AgNW-TiO core–shell structure as f-TCE delivered excellent stability after 5000 times of bending and number of peeling off cycles. The as prepared f-TCE delivered sheet resistance (Rs) of 8.61 Ω/sq with transmittance of 85 % at 550 nm and Rs of 4.2 Ω/sq with transmittance of 81 % when cured at 250 °C. The surface temperature of f-TCE was found to increase up to 90 °C in 40 s after applying 4 V of supply indicating its potential as transparent heater. In addition to that the CIGS solar cell fabricated by utilization of our f-TCE exhibited efficiency of 9.6 %, demonstrating its applicability for photovoltaic applications.