The Interaction between PEDOT/PSS Gate and sub-μ low-k Insulator for All Printed OFETs

In all printed OFETs with Poly(3,4-ethylenedioxythiophene)/ poly(styrenesulfonate) (PEDOT/ PSS) gate, offset printing and gravure of electrically dense sub-$\mu$ insulators from polyvinylphenol (PVPh), polyvinyl alcohol (PVOH) and poly(methyl methacrylate) (PMMA) as well as other organic and inorganic materials turned out to be problematic due to the most reactive part of the gate material- the negative sulfonate ions from PSS. The present paper investigates the nature of the interaction between PSS and PVOH sub-$\mu$ insulator explored by infrared spectroscopy and electrical methods. Some evidence is obtained that most probably OH- and not sulfonate ions are responsible for creating channels, penetrated by PEDOT/PSS nano dispersion applied as gate.