Spectroelectrochemical studies of the C₁₄-alkyl derivative of poly(3,4-ethylenedioxythiophene) (PEDT)

Spectroelectrochemical properties and electrical resistivity of an alkyl derivative of the poly(3,4-ethylenedioxythiophene), PEDT-C₁₄ were investigated. The oxidative doping process of this polymer was studied by means of cyclic voltammetry, UV-vis-NIR optical absorption, Raman scattering and Electron Paramagnetic Resonance (EPR). The in situ conductivity on a Pt microelectrode was also monitored. Optical spectroscopies permit to follow the evolution of the different species that are present. Combination of these different techniques leads to the characterization of the charged species that are induced by doping, and a mechanism of the modification of the electronic structure of PEDT-C₁₄ is proposed.