Composites of Shellac and Silver Nanowires as Flexible, Biobased, and Corrosion-Resistant Transparent Conductive Electrodes

Silver nanowires (AgNWs) are one of the most promising materials to replace indium tin oxide as transparent conductive electrodes (TCEs) in next-generation flexible optoelectronic devices. AgNWs are more environmentally friendly than indium tin oxide, and additionally offer solution processability, high conductivity, and high optical transparency. However, a barrier to practical use is the tendency of AgNWs to corrode in the ambient environment, which damages the AgNW network and reduces life span. This study presents the use of shellac, and eco-friendly natural biopolymer, as a planarizing and protective matrix for AgNWs. Shellac has not been significantly explored in flexible electronics but has a long history as a protective coating due to its high gas barrier properties. We report the first example of a shellac-based TCE comprising a AgNW network embedded at the surface of a shellac matrix. Shellac-AgNW TCEs provide high conductivity, optical transparency, and mechanical stability. The shellac matrix protects AgNWs from corrosion in challenging environments of humidified air and corrosive acid vapors. As concerns about the environmental persistence of synthetic polymers intensify, we demonstrate that shellac is a promising material for next generation flexible electronics.