In-situ resonant raman spectroelectrochemical study of p-doped poly(p-phenylene vinylene): influence of the conversion

We purpose to study the electronic structure modifications induced by p type doping of poly(p-phenylene vinylene) (PPV). PPV is obtained by thermal and photochemical conversion of tetrahydrothiophenium precursor. These both polymers have some differences in their conjugation length distribution. The resonant Raman spectra analysis coupled to a dynamic model permits us to describe vibrational modes corresponding to the different localized charged excitations produced along the chain of these polymers after doping. The characteristics of a quinoid structure are put in evidence. This one is independent of the conversion conditions of PPV and of the counter-ion nature.