Influence of base inhibitor and surfactant on the electrical and physicochemical properties of PEDOT-SiO2 hybrid conductive films

Abstract

This paper describes the synthesis of poly(3,4-ethylenedioxythiophene)-SiO2 hybrid conductive films possessing superior mechanical properties and improved opto-electrical properties. A mixture of a 3,4-ethylenedioxythiophene (EDOT) monomer and an optimized amount of a tetraethyl orthosilicate (TEOS) SiO2 precursor was co-vaporized and synchronously polymerized on a ferric p-toluenesulfonate (FTS)-coated poly-(ethylene terephthalate) (PET) substrate. The opto-electrical properties of the mechanically robust PEDOT-SiO2 hybrid films were improved by adding a poly(ethylene glycol)-poly(propylene glycol)-poly(ethylene glycol) (PEG-PPG-PEG) triblock copolymer surfactant and an imidazole base inhibitor to the FTS oxidant solution. These two additives served to control polymerization and prohibit crystallization, resulting in conductive thin films with smooth and homogeneous morphologies. Additionally, the additives improved the physicochemical properties of the films, as determined by their pencil hardness, solvent resistance, and scratch resistance. Finally, these additives yielded hybrid thin films that showed good electrical and optical stability over time. Open image in new window