Dynamics of polarons and bipolarons with interchain coupling in conjugated polymers

Abstract

ABSTRACT:The interchain and interactions of two parallel chains are studied numerically through the dynamics of charged polaron and bipolaron in the presence of an electric field by using the Pariser-Parr-Pople model combined with the Su-Schrieffer-Heeger model. The electron-lattice coupling and the Brazovskii-Kirovatype symmetry-breaking interaction are introduced in the current model. The electric field is introduced in terms of a time-dependent vector potential that is included in the Hamiltonian through a Peierls substitution of the phase factor to the transfer integral. The charge-transfer probability between charged polarons and bipolarons belonging to neighboring chains is determined by the numerical resolution of the equations of motion within the unrestricted Hartree-Fock approximation. The effects of confinement on the polaron and bipolaron motion are determined.

A review on nonlinear DNA physics

“…7: 200774 The difference in the numerical prefactor in the last equation arises as a consequence of the fact that it is addressed to the highly anisotropic but essentially 3D structure, while the result presented by equation (4.18) concerns the two chain macromolecular system. Let us mention here that similar results with our prediction previously were reported in the papers devoted to polarons in conducting polymers [114][115][116][117][118][119][120]. In the paper of Mizes & Conwell [114], the influence of the inter-chain coupling on the large polaron stability in conducting polymers have been numerically studied within the extended Su-Schrieffer-Heeger (SSH) model.…”

“…Let us mention here that similar results with our prediction previously were reported in the papers devoted to polarons in conducting polymers [114][115][116][117][118][119][120]. In the paper of Mizes & Conwell [114], the influence of the inter-chain coupling on the large polaron stability in conducting polymers have been numerically studied within the extended Su-Schrieffer-Heeger (SSH) model.…”

Enhanced Charge Transfer Doping Efficiency in J-Aggregate Poly(3-hexylthiophene) Nanofibers

“…Corresponding Raman spectra generated on resonance with F 4 -TCNQ – :P3HT + absorption bands show evidence of P3HT quinoid distortions in J-type nanofibers, indicating efficient intrachain hole polaron delocalization. − Interestingly, integrated EPR spin densities decrease significantly for F 4 -TCNQ loadings >25% in J-aggregates. We attribute this effect to antiferromagnetic exchange coupling between hole polaron spins on neighboring π-stacked P3HT chains resulting in interchain, spinless bipolarons. , However, these interchain polaron interactions do not appear to significantly perturb one photon absorption selection rules governing the absorption strength of F 4 -TCNQ – :P3HT + species, which continues to increase over the same loading range. The results demonstrate the importance of nanomorphology and purity of aggregates in determining doping efficiency that are not readily discernible from studies of conventional thin films.…”

“…We attribute this effect to antiferromagnetic exchange coupling between hole polaron spins on neighboring π-stacked P3HT chains resulting in interchain, spinless bipolarons. 28,29 However, these interchain polaron interactions do not appear to significantly perturb one photon absorption selection rules governing the absorption strength of F 4 -TCNQ − :P3HT + species, which continues to increase over the same loading range. The results demonstrate the importance of nanomorphology and purity of aggregates in determining doping efficiency that are not readily discernible from studies of conventional thin films.…”

Molecular Photovoltaics in Nanoscale Dimension

“…However, the inherent problem of such ordered systems is the interchain coupling. The charge-transfer probability between charged polarons and bipolarons belonging to neighboring chains [ 5 ], along with high electron-phonon coupling and the Peierls transition, leads to charge trapping [ 6 ]. The strong coupling could result in low mobility and even induce pseudo-gaps [ 7 ].…”