Polymer-Embedded Silver Microgrids by Particle-Free Reactive Inks for Flexible High-Performance Transparent Conducting Electrodes

Abstract

We report on the fabrication and characterization of polymer-embedded silver (Ag) microgrid structures using a particle-free reactive Ag ink for flexible high-performance transparent conductive electrodes. The Ag microgrids are cured at low temperatures and embedded directly into flexible polyethylene terephthalate (PET) films to create structures needed for high transparency and low sheet resistance. The conductive grids demonstrate 91.8% transmission and a sheet resistance of 0.88 Ω/sq corresponding to an optical conductivity ratio σdc/σop of nearly 4500 with gridlines of 10 μm width. The microgrids may be fabricated with gridlines down to 3.5 μm width. The fabrication of microgrids from a particle-free reactive ink results in several enhancements compared to microgrids fabricated from particle-based conductive Ag inks. The use of particle-free ink offers about 2.5 times higher conductivity, over 3 times lower surface roughness, and better stability under mechanical adhesion, bending, and folding tests. Our results demonstrate the following: (1) a scalable approach to microgrid manufacturing, (2) microgrids with nearly the best transparent electrode performance properties, and (3) the clear benefit of the paradigm of particle-free conductive inks compared to conventional nanoparticle inks.