Monte-Carlo simulation of linear sweep voltammograms during redox switching of conducting polymers

We propose a derived approach from the model of the moving front, that incl udes ionic transport in the redox process of conducting polymers. The movin g front is the border between the insulating and conducting zones, where ox idation takes place. In our approach, the conversion of a polymer site from reduced to oxidised state requires simultaneously an electron transfer wit h the electrode and the presence of a dopant ion. When both conditions are fulfilled, oxidation occurs: the dopant ion remains trapped and the front i s shifted toward the neighbour site. Ionic motion inside the film is assume d to be one-dimensional diffusion, and is simulated by Monte-Carlo. Simulat ed voltammograms are thus obtained and analysed as a function of scan rate. A diffusion limited regime was actually observed at low scan rate, but the high scan rate behaviour is somewhat different from experimental profiles. This tends to show the necessity to include a migration component in the d opant transport, in order td improve the description of the redox process o f conducting polymers. (C) 1999 Elsevier Science Ltd. All rights reserved.