An electrochemical impedance analysis of the doping kinetics of polydicarbazole films is reported. Polymer films of varying thickness were analyzed using an impedance model that considers spatially-restricted diffusion of ionic species. The main bulk parameters for diffusion and charge accumulation during doping were determined from fits. These parameters resulted independent of film thickness after considering the experimental error. The equilibrium (bulk) capacitance C-0 varies in the range of 100-800 F cm(-3). The chemical diffusion coefficient D varies within the range of 10(-10) to 10(-8) cm(2) s(-1) and increases as the steady-state potential reaches the oxidation peak potential. (C) 2004 Elsevier Ltd. All rights reserved.