TY - JOUR
T1 - Origin of line broadening in the electronic absorption spectra of conjugated polymers
T2 - Three-pulse-echo studies of MEH-PPV in toluene
AU - Scholes, Gregory D.
AU - Larsen, Delmar S.
AU - Fleming, Graham R.
AU - Rumbles, Garry
N1 - Copyright:
Copyright 2017 Elsevier B.V., All rights reserved.
PY - 2000
Y1 - 2000
N2 - Integrated three-pulse stimulated echo peak shift data are compared for N, N-bis-dimethylphenyl-2,4,6,8-perylenetetracarbonyl diamide and (Formula presented) (MEH-PPV) in toluene solvent. These two molecules represent a model probe of solvation dynamics and a prototypical soluble, electroluminescent conjugated polymer, respectively. The results indicate that it is inappropriate to describe the linear absorption spectrum of MEH-PPV as being primarily inhomogeneously broadened. Conformational disorder along the polymer backbone gives rise to an ensemble of polyene electronic oscillators that are strongly coupled to each other. As a consequence, fluctuations in the electronic energy gap on a time-scale of 50-fs derive primarily from bath-mediated exciton scattering. The data reported here provide an explanation for the broad, structureless electronic absorption of MEH-PPV. This interpretation provides a valuable insight into the nature of the initial photoexcited state, and the efficient population of the emissive state.
AB - Integrated three-pulse stimulated echo peak shift data are compared for N, N-bis-dimethylphenyl-2,4,6,8-perylenetetracarbonyl diamide and (Formula presented) (MEH-PPV) in toluene solvent. These two molecules represent a model probe of solvation dynamics and a prototypical soluble, electroluminescent conjugated polymer, respectively. The results indicate that it is inappropriate to describe the linear absorption spectrum of MEH-PPV as being primarily inhomogeneously broadened. Conformational disorder along the polymer backbone gives rise to an ensemble of polyene electronic oscillators that are strongly coupled to each other. As a consequence, fluctuations in the electronic energy gap on a time-scale of 50-fs derive primarily from bath-mediated exciton scattering. The data reported here provide an explanation for the broad, structureless electronic absorption of MEH-PPV. This interpretation provides a valuable insight into the nature of the initial photoexcited state, and the efficient population of the emissive state.
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U2 - 10.1103/PhysRevB.61.13670
DO - 10.1103/PhysRevB.61.13670
M3 - Article
AN - SCOPUS:0001007519
VL - 61
SP - 13670
EP - 13678
JO - Physical Review B-Condensed Matter
JF - Physical Review B-Condensed Matter
SN - 1098-0121
IS - 20
ER -