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2009-11-17 - Article/Dans un journal avec peer-review - Anglais - 1 page(s)

Singh J., Bittner E.R., Beljonne David , Scholes G.D., "Fluorescence Depolarization in Poly[2-methoxy-5-((2-ethylhexyl)oxy)-1-4-phenylenevinylene]: Sites versus Eigenstates Hopping" in Journal of Chemical Physics, 131, 19, 194905

  • Edition : American Institute of Physics, New York (NY)
  • Codes CREF : Spectroscopie [électromagnétisme, optique, acoustique] (DI1255)
  • Unités de recherche UMONS : Chimie des matériaux nouveaux (S817)
  • Instituts UMONS : Institut de Recherche en Science et Ingénierie des Matériaux (Matériaux)
Texte intégral :

Abstract(s) :

(Anglais) We report upon a theoretical study of singlet exciton migration and relaxation within a model conjugated polymer chain. Starting from poly(2-methoxy-5-((2-ethylhexyl)oxy)-1,4- phenylenevinylene) polymer chains, we assume that the pi-conjugation is disrupted by conformational disorder of the chain itself, giving rise to a localized Frenkel exciton basis. Electronic coupling between segments as determined by the coupling between the transition densities of the localized excitons gives rise to delocalized exciton states. Using a kinetic Monte Carlo approach to compute the exciton transfer kinetics within the manifold of either the dressed chromophore site basis or dressed eigenstate basis, we find that the decay of the polarization anisotropy of the exciton is profoundly affected by the delocalization of the exciton over multiple basis segments. Two time scales emerge from the exciton migration simulations: a short, roughly 10 ps, time scale corresponding to rapid hopping about the initial excitation site followed by a slower, 180 ps, component corresponding to long range hopping. We also find that excitations can become trapped at long times when the hopping rate to lower-energy states is longer than the radiative lifetime of the exciton.

Notes :
  • (Anglais) Publié en ligne le 17 novembre 2009
Identifiants :
  • DOI : 10.1063/1.3259549