Triplet excitation transfer in glassy systems: Spatial and spectral diffusion

Naoki Ito, Ranko Richert

Research output: Contribution to journalArticle

4 Citations (Scopus)

Abstract

Triplet excitation transfer among benzophenone molecules dissolved in glassy 2-methyltetrahydrofuran is studied by recording the emission and the optical depolarization as a function of wavelength and time. The transport mechanism is based upon exchange interaction and subject to the random character of both jump distances and site energies. Optical anisotropy data are used to gauge the probability of an excitation to remain on its original site. The anisotropy is observed to decrease by a factor of 2 from high to low energies within the inhomogeneously broadened emission band, clearly indicating hopping-mediated thermalization within the density of states. Within their excited-state lifetime the excitons do not reach the steady-state energies, but solvation allows the observation of that energy level. Unexpectedly, we find that the transfers at very short times do not contribute as much to spectral diffusion as the subsequent transport. Because the short-time hops target sites as close as ≈1 nm, this observation suggests spatially correlated site energies for these short distances.

Original languageEnglish (US)
Article number234508
JournalJournal of Chemical Physics
Volume122
Issue number23
DOIs
StatePublished - Jun 15 2005

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Electron energy levels
atomic energy levels
Optical anisotropy
Exchange interactions
Solvation
Depolarization
Excited states
optical depolarization
Gages
Anisotropy
Wavelength
anisotropy
Molecules
energy
excitation
solvation
energy levels
recording
excitons
life (durability)

ASJC Scopus subject areas

  • Atomic and Molecular Physics, and Optics

Cite this

Triplet excitation transfer in glassy systems : Spatial and spectral diffusion. / Ito, Naoki; Richert, Ranko.

In: Journal of Chemical Physics, Vol. 122, No. 23, 234508, 15.06.2005.

Research output: Contribution to journalArticle

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