Transparent Conductors Printed from Grids of Highly Conductive Silver Nanosheets

Transparent conductors(TCs) represent key componentsin many applicationsfrom optoelectronic devices to electromagnetic shielding. While commercialapplications typically use thin films of indium tin oxide, this materialis brittle and increasingly scarce, meaning higher performing andcheaper alternatives are sought after. Solution-processible metalswould be ideal owing to their high conductivities and printability.However, due to their opacity to visible light, such films need tobe very thin to achieve transparency, thus limiting the minimum resistanceachievable. One solution is to print metallic particles in a gridstructure, which has the advantages of high tunable transparency andresistance at the cost of uniformity. Here, we report silver nanosheetsthat have been aerosol jet printed into grids as high-performancetransparent conductors. We first investigate the effect of annealingon the silver nanosheets where we observe the onset of junction sinteringat 160 & DEG;C after which the silver network becomes continuous.We then investigate the effect of line width and thickness on theelectrical performance and the effect of varying the aperture dimensionson the optical performance. Using these data, we develop simple models,which allow us to optimize the grid and demonstrate a printed transparentconductor with a transmittance of 91% at a sheet resistance of 4.6 & omega;/sq.