Determination of mobilities of charge carriers in electrochemically anion-doped polythiophene film

Mobilities of positive charge carriers in a polythiophene film at different oxidation stages are evaluated on the bases of elaborate electrochemical measurements. The mobility in the low doping regime, most likely that of polarons, is 10(-6) cm(2) V-1 s(-1). The mobility starts to increase at around 0.2 mol% doping level and reaches 0.5 X 10(-2) cm(2) V-1 s(-1) in the heavily doped region. The drastic mobility increase by doping manifests changes in nature and/or kind of charge-carrying species, or the switching of conduction mechanisms in the ClO4-doped polythiophene film. (C) 2000 Elsevier Science B.V. All rights reserved.