Electrodeposited Composite of Poly-3,4-ethylenedioxythiophene with Fullerenol Photoactive in the Near-IR Range

The electrochemical polymerization of 3,4-ethylenedioxythiophene in the presence of a water-soluble Na⁺-containing fullerene with hydroxyl groups is studied. The monitoring of the electrosynthesis process by spectroscopic methods shows that during the polymerization of 3,4-ethylenedioxythiophene, fullerenol incorporates into the film composition, regardless of the fullerenol concentration used. The electronic structure, morphology, spectroelectrochemical and electrochemical properties, and near-IR photoconductivity of the poly-3,4-ethylenedioxythiophene–fullerenol composite films are studied for the first time. A mechanism of photoconductivity is proposed, related to the fact that during the photoexcitation of the composite, the electron transfer from the polaron (bipolaron) state of poly-3,4-ethylenedioxythiophene to the LUMO level of fullerenol increases the concentration of photogenerated charge carriers.