Electrochemical and photoelectrochemical behaviour of poly-3-methylthiophene and polybithiophene in non-aqueous solutions - 1. Dark and light processes in systems with and without cathodic doping

The electrochemical as well as the photoelectrochemical behaviour of poly-3 -methylthiophene and polybithiophene in systems with and without the possib ility of cathodic doping was studied. Using electrochemical impedance measu rements it was demonstrated that in both types of systems the pholoelectroc hemical processes on such polymers involved photoelectrochemical undoping o f the polymer itself as well as the photoelectrochemical reduction of a com ponent of an external odor couple in the solution. In systems with cathodic doping, in addition to these two processes, photoassisted cathodic doping of the polymer is observed. The model of photoelectrochemical processes on polymer electrodes is discussed. (C) 1999 Elsevier Science S.A. All rights reserved.