The effect of tannic acids on the electrical conductivity of PEDOT:PSSFilms

Conductive poly(ethylenedioxythiophene):polystyrene sulfonate (PEDOT:PSS) films with good transparency and great flexibility are highly demanded in various areas. A facile method is employed to produce conductive films with UV-blocking properties. The direct addition of tannic acids (TAs) powders into PEDOT:PSS aqueous suspension lead to the enhancement of electrical conductivity of TA:PEDOT:PSS (TAPE) films. This improvement owes to the conformation change of the PEDOT chains from benzoid to quinoid configuration. Further investigations revealed the absence of phase separation in the highest conductive TAPE film. TAPE films are smoother and thicker than the pristine PEDOT:PSS film owing to the high density and good solubility of TAs. The absorbance increases with the increase of the TA content in TAPE films. The core levels of oxygen and sulfur atoms in PEDOT and PSS have been studied, which illustrate the composition of TAPE films.