Electrical conductivities of ternary polyelectrolyte complexes based on PEDOT and sulfonate polymers with various processing treatments

A polyelectrolyte complex of poly(3,4-ethylenedioxythiophene) (PEDOT) and polystyrene sulfonate (PSS) has shown an electrical conductivity of >10³ S/cm through post-deposition processing and visible transparency of >80%. The composite, PEDOT:PSS in short, is therefore widely used in various industries. In this work, we synthesized ternary polymer systems using PEDOT, PSS, and various third components, including poly(vinyl sulfonate) (PVS), by in-situ polymerization of monomers in presence of the sulfonate polymers. We then studied the effects of compositions and processing parameters on the electrical properties of the ternary composites. We confirmed that the conductivity of as-synthesized composite films reached ~20 S/cm when PSS:PVS=1:1, which was three times higher than that of the as-prepared binary PEDOT:PSS (~7 S/cm). We also applied various processing methods on the ternary polymer systems by varying the dipping solvents and studied the UV-Vis-NIR absorption characteristics and the electrical conductivities. Different degrees of property changes were observed depending on the processing conditions.