Nucleation and growth of LiCF3SO3-doped polyalkylthiophenes

The effect of monomer and electrolyte (LiCF3SO3) concentrations on the nucl eation and growth processes of polythiophene, poly(3-methythiophene) and po ly(3-hexylthiophene) electrogenerated on a platinum electrode in an acetoni trile media were studied. The current transients were fitted using a mathem atical equation that considers up to seven contributions, each of them repr esenting a different classical nucleation and growth mechanism. The results indicate that the electrogeneration of polythiophene and poly(3-methylthio phene) films follow a similar mechanism, two-dimensional processes being de tected at short reaction times, the overall processes being governed at lon ger reaction time by an instantaneous three-dimensional nucleation under ch arge control mechanism. The electrogeneration of poly(3-hexylthiophene) fil ms, however, takes place without overlapping of nuclei, the process now bei ng governed by an instantaneous nucleation three-dimensional diffusion cont rol mechanism. (C) 2001 Elsevier Science Ltd. All rights reserved.