Substrate treatment and drying conditions effect on the properties of roll-to-roll gravure printed PEDOT:PSS thin films

The optical, structural and electrical properties of poly(3,4-ethylenedioxythiophene):poly(4-styrenesulfonic acid) (PEDOT:PSS) thin films printed by roll-to-roll gravure have been investigated. Corona treatment has been applied to enhance the adhesion of PEDOT:PSS on PolyEthylene Terephthalate (PET) web. It has been found that there was a stronger in-depth surface modification of PET with the increase of corona efficiency; however, the adhesion of PEDOT:PSS was not actually affected. Also, Spectroscopic Ellipsometry and Atomic Force Microscopy have been used to extract information on the mechanisms that define PEDOT:PSS properties. The increase of the drying temperature of the PEDOT:PSS films has been found to reduce the remaining water inside the films and lead to the decrease of the PEDOT:PSS particles size.

► Drying conditions effect on the optical, electrical and structural characteristics of R2R gravure printed PEDOT:PSS thin films
► Insight on microstructural, compositional and electrical characteristics of the PEDOT:PSS films by Spectroscopic Ellipsometry combined with the AFM results
► Drying temperature increase leads to less remained water volume fraction, smaller particles, lower film roughness and finally better conductivity
► Transformation of spherical particles in solution to pancakes in thin films is attributed to the drying process
► The increase of corona efficiency leads to a deeper PET surface modification without affecting the adhesion of PEDOT:PSS