Highly conductive PEDOT:PSS with enhanced chemical stability

Abstract

As a family of conjugated polymers, poly(3,4-ethylenedioxythiophene):poly(styrene-sulfonate) (PEDOT:PSS) has been extensively investigated because of its high conductivity, solution processability, mechanical flexibility and transparency. However, poor chemical stability makes this conducting polymer difficult for practical application. In addition, a harsh doping condition (eg, aqueous H2SO4) is required to obtain high conductivity. By employing perfluorooctane sulfonic acid (PFOSA) as a mild dopant, we were able to fabricate a PEDOT:PSS film with high conductivity (ca. 1700 S/cm) as well as significantly improved chemical and long term stability. The results of detailed spectroscopic and morphological studies show that the superhydrophobic tails and hydrophilic head-groups of PFOSA in the doped PEDOT:PSS are critical factors responsible for the improved properties of the conducting polymer. Finally, owing to its mild nature, PFOSA doping can be employed to fabricate a transparent, flexible and conducting PEDOT:PSS coated PET film.