ESR study of electrochemical doping in the conducting polymer polypyrrole

Genoud, F.; Guglielmi, Marina Nella; Nechtschein, M.; Geniès, E.M.; Salmón, Manuel

doi:10.1103/physrevlett.55.118

Cited by 225 publications

(80 citation statements)

References 12 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…15 There is a considerable variation, however, in the experimental data on PPy doping. 12,13,[16][17][18] The sub-band transitions of doped COPs were rationalized originally in terms of bipolaron formation since there is no correlation between ESR signals and conductivity. 9,[19][20][21][22] Preference for bipolarons has been questioned by some experimentalists from the start, 17,18,[23][24][25][26] but others rationalized their observations in terms of bipolarons.…”

Section: Introductionmentioning

confidence: 99%

“…12,13,[16][17][18] The sub-band transitions of doped COPs were rationalized originally in terms of bipolaron formation since there is no correlation between ESR signals and conductivity. 9,[19][20][21][22] Preference for bipolarons has been questioned by some experimentalists from the start, 17,18,[23][24][25][26] but others rationalized their observations in terms of bipolarons. 13,16,22 Especially after the doping behavior of monodisperse polyenes [27][28][29] and oligothiophenes (OTs) [30][31][32][33][34][35][36][37][38][39][40][41] was investigated in solution, the bipolaron model was challenged.…”

Section: Introductionmentioning

confidence: 99%

“…[49][50][51] In the oligomer studies the issue of bipolaron formation was not addressed and the interpretation of polymer results remains controversial. 8,12,13,16,17,20,22,23,25,[52][53][54][55] Electronic structures of PPy and OPs have been investigated theoretically before; 20,[56][57][58][59][60][61][62][63][64][65][66][67][68][69][70] however, we are not aware of calculations of absorption spectra during the doping process of pyrrole oligomers or polymers. We have recently calculated such spectra for polyenes 71 and OTs.…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Theoretical Modeling of the Doping Process in Polypyrrole by Calculating UV/Vis Absorption Spectra of Neutral and Charged Oligomers

Okur

Salzner

2008

J. Phys. Chem. A

View full text Add to dashboard Cite

Changes in absorption spectra during doping of oligopyrroles were investigated with time-dependent density functional theory on optimized structures of neutral, singly, and doubly charged pyrrole oligomers with up to 24 rings. In the absence of counterions, defects are delocalized. Counterions induce localization. For dications two polarons on the same chain are preferred over a bipolaron. Intragap absorptions arise in charged species, no matter whether defects are localized or delocalized. Cations and dications give rise to two sub-band transitions. The cation peaks have lower energies than those of dications. The first excitations of cations have lower oscillator strengths than the second; for dications the second peak is weaker than the first. For very long oligomers, the second sub-band absorption vanishes and a third one appears at higher energy. The behavior of pyrrole oligomers is analogous to that of thiophene oligomers. Theoretical UV spectra for cations and dications of short oligomers (six to eight rings) match experimental spectra of polypyrrole at low and at high doping levels, respectively. The error in the theoretical calculations is about 0.4 eV, slightly larger than for thiophene oligomers at the same level of theory.

show abstract

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Theoretical Modeling of the Doping Process in Polypyrrole by Calculating UV/Vis Absorption Spectra of Neutral and Charged Oligomers

Okur

Salzner

2008

J. Phys. Chem. A

View full text Add to dashboard Cite

show abstract

“…1 Several experiments have demonstrated the existence of bipolarons, especially in doped polymers. [2][3][4][5] Some of the early studies concentrated on the stability of bipolaron. [6][7][8][9][10] It is now clear that both the electron-phonon coupling and the electron-electron interaction play an important role in forming bipolarons: at low concentration of carriers, carriers are more likely in the form of polarons, while at high concentration of carriers they tend to favor bipolarons.…”

Section: Introductionmentioning

confidence: 99%

Bipolaron recombination in conjugated polymers

Sun

Stafström

2011

The Journal of Chemical Physics

View full text Add to dashboard Cite

By using the Su-Schrieffer-Heeger model modified to include electron-electron interactions, the Brazovskii-Kirova symmetry breaking term and an external electric field, we investigate the scattering process between a negative and a positive bipolaron in a system composed of two coupled polymer chains. Our results show that the Coulomb interactions do not favor the bipolaron recombination. In the region of weak Coulomb interactions, the two bipolarons recombine into a localized excited state, while in the region of strong Coulomb interactions they can not recombine. Our calculations show that there are mainly four channels for the bipolaron recombination reaction: (1) forming a biexciton, (2) forming an excited negative polaron and a free hole, (3) forming an excited positive polaron and a free electron, (4) forming an exciton, a free electron, and a free hole. The yields for the four channels are also calculated.

show abstract

“…These depend on the symmetry of the polymers, [1][2][3] doping concentration, [4][5][6] and external force. 7, 8 Because each excitation has characteristic spin-charge relation, they can be probed by such as susceptibility measurements 6,9 or optical spectroscopy measurements. [10][11][12] Recently, the intersystem crossing of excitons in heterojunction systems was proved to be affected by a magnetic field.…”

Section: Introductionmentioning

confidence: 99%

Probing spin-charge relation by magnetoconductance in one-dimensional polymer nanofibers

et al. 2012

View full text Add to dashboard Cite

Polymer nanofibers are one-dimensional organic hydrocarbon systems containing conducting polymers where the nonlinear local excitations such as solitons, polarons, and bipolarons formed by the electronphonon interaction were predicted. Magnetoconductance (MC) can simultaneously probe both the spin and charge of these mobile species and identify the effects of electron-electron interactions on these nonlinear excitations. Here, we report our observations of a qualitatively differentMC in polyacetylene (PA) and in polyaniline (PANI) and polythiophene (PT) nanofibers. In PA, the MC is essentially zero, but it is present in PANI and PT. The universal scaling behavior and the zero (finite)MC in PA (PANI and PT) nanofibers provide evidence of Coulomb interactions between spinless charged solitons (interacting polarons which carry both spin and charge). Polymer nanofibers are one-dimensional organic hydrocarbon systems containing conducting polymers where the nonlinear local excitations such as solitons, polarons, and bipolarons formed by the electron-phonon interaction were predicted. Magnetoconductance (MC) can simultaneously probe both the spin and charge of these mobile species and identify the effects of electron-electron interactions on these nonlinear excitations. Here, we report our observations of a qualitatively different MC in polyacetylene (PA) and in polyaniline (PANI) and polythiophene (PT) nanofibers. In PA, the MC is essentially zero, but it is present in PANI and PT. The universal scaling behavior and the zero (finite) MC in PA (PANI and PT) nanofibers provide evidence of Coulomb interactions between spinless charged solitons (interacting polarons which carry both spin and charge). Disciplines Physical Sciences and Mathematics | Physics

show abstract

ESR study of electrochemical doping in the conducting polymer polypyrrole

Cited by 225 publications

References 12 publications

Theoretical Modeling of the Doping Process in Polypyrrole by Calculating UV/Vis Absorption Spectra of Neutral and Charged Oligomers

Theoretical Modeling of the Doping Process in Polypyrrole by Calculating UV/Vis Absorption Spectra of Neutral and Charged Oligomers

Bipolaron recombination in conjugated polymers

Probing spin-charge relation by magnetoconductance in one-dimensional polymer nanofibers

Contact Info

Product

Resources

About