Complementary nature of voltabsorptiometric, nanogravimetric and in situ conductance results for the interpretation of conducting polymers’ redox transformation

Abstract

During the last decade the hyphenation of in situ spectrovoltammetry and a.c. conductance techniques has been realized and used for the redox transformation process of conducting polymers. Since charge carriers can be identified spectrally, the simultaneous monitoring of these two signals may answer the questions, how the name-giving property of this class of polymers is connected to the formation of the charge carriers, moreover, which spectrally distinguishable charge carrier is primarily responsible for the development of the conducting state. In the present work multi-faceted studies on numerous systems are presented to illustrate how results obtained by using different in situ electrochemical techniques can complete each other. Systematic measurements taken on differently substituted polythiophene films showed that combined spectral and conductance changes can be interpreted on the grounds of electrogravimetric observations. On this basis the question, which spectrally distinguishable charge carrier is primarily responsible for the development of the conducting state and why, can be answered by considering the mobility of the doping anion.