Influence of the working electrode metal on the polythiophene structure. Raman and x-ray photoelectron spectroscopic investigations of the aluminium/polythiophene interface

Abstract

Polythiophene films of different thicknesses were obtained by electrochemical polymerization of thiophene on to oxidizable (Zn, Fe and Al) and noble (Pt) metals. Resonance Raman and x-ray photoelectron analyses indicated, on the one hand, a better structural organization of the films synthesized on to Zn, Fe and Al in comparison with those deposited on to Pt and, on the other hand, an increase in disorder with the film thickness for each metal. In the case of Al electrodes, on the basis of experimental data, it was suggested that during the first stages of electropolymerization, interactions between Al and Cα atoms occur at the interface and lead to the formation of real covalent bonds between the metal and the organic coating. This, in part, could explain the strong adhesion of the polymer on the electrode surface, its significant thermal stability towards the laser local heating and the enhancement of the Raman intensity. © 1998 John Wiley & Sons, Ltd.