Potential dependence of polaron and bipolaron densities in conducting polymers: theoretical description beyond the Nernst equations

Electrochemical impedance analysis of the redox switching hysteresis of poly(3,4-ethylenedioxythiophene) films

“…However, it is evident that R ct depends on the actual oxidation state of the polymer films (a function of the polaronic species density [18]) and therefore also exhibits hysteretic behavior ( Fig. 6(b)).…”

A passivation mechanism of doped polyaniline on 410 stainless steel in deaerated H2SO4 solution

“…Meanwhile, the S/N proportion decreases from 0.53 to 0.37, which indicates dedoping has occurred during potentiostatic polarization. The probable causes are that, as a conjugated conductive polymer, PANI stores a large charge capacity by absorbing many protons and counter ions [30,[37][38][39][40], when the polarize potential is relatively positive, PANI is polarized slightly resulting in a slight transformation in the charge delocalization. The slight reduction of polyaniline represents its electrochemical dedoping process reacting as the Eq.…”

Transport and reactions in doped conjugated polymers: Electrochemical processes and organic devices

“…Higher densities in inorganic semiconductors require Fermi-Dirac statistics and the exponential dependence is replaced by the Fermi integral F 1/2 . For polarons and bipolarons as charged states of polymer chains the formation of a polaron lattice or a bipolaron lattice has to be considered [21,25], or the density can be determined in organics by a Gaussian density of states. In all these cases the appropriate dependence of c(E) or p(e F ) has to be taken into account in the basic equations (6)- (8).…”

“…At very large oxidation degree one has the formation of polaron or bipolaron bands (see e.g. [21,25]). This case will not be considered here.…”

“…Though BPs have been considered in analyzing CV data [20,21], they have been included only recently in the electrochemical transmission line model [22]. Kirova and Brazovskii (KB) [19] assumed that the BP formation by pair collision of Ps faces strong Coulomb repulsion and proposed a scenario with the formation of different complexes from Ps, BPs and Cs.…”