Printability of functional inks on multilayer curtain coated paper

Abstract

Printability of functional inks on multilayer curtain coated substrates was investigated. The inks represent those commonly used to produce solution processable electronic devices, such as organic transistors. The substrate, which combines sufficient barrier and printability properties for printed functional devices, was manufactured utilizing high speed curtain coating technique. The coating structure consists of a mineral pigment layer coated on top of a barrier layer. The combination of the two layers allows for controlling the absorption of ink solvents. By adjusting the thickness, porosity and surface energy of the top-coating the printability can be tuned for various functional inks. Focus was set on printing conducting silver and carbon inks, both with nano- and micrometer sized particles, as well as printing of an organic semiconductor, poly(3-hexylthiophene). The pore volume in the top-coating determined the spreading of the micrometer sized silver ink as well as the amount semiconductor per area required, whereas the pore size was the determining factor regarding penetration of the nano-sized silver ink. As a proof of concept hygroscopic insulator field effect transistors were printed on the multi-layer curtain coated paper using a custom-built roll to roll hybrid printer.