Electrochemical impedance spectroscopy characterization of conducting polymer/TiO2 nanotube array hybrid structures

•Hybrid structures are made of conducting polymers on nanostructured titanium oxide.•Impedance measurements are performed on hybrid structures.•A model from the literature is adapted to the hybrid structures.•Modification of the semiconducting behavior is observed in the presence of polymers.

The model suggested by Deslouis and co-workers [14] for describing the behavior of polypyrrole deposited on a metallic substrate is here used for conducting polymers deposited on a nanostructured 3D semiconducting substrate. Impedance measurements were performed on a titanium oxide nanotubular array in the presence of two types of conducting polymers: polypyrrole and poly(3,4-ethylenedioxythiophene), highlighting the modification of the semiconducting properties of the substrate induced by the polymer deposition. The model is shown to be particularly well adapted for the PEDOT/TiO2 hybrid structure, providing a valuable tool for characterizing the interaction between the conducting polymer and the semiconducting substrate.