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dc.contributor.authorHayes, Sophia C.en
dc.contributor.authorSilva, C.en
dc.creatorHayes, Sophia C.en
dc.creatorSilva, C.en
dc.description.abstractWe present ultrafast transient absorption spectra of two oligofluorene derivatives in dilute solution. These spectra display a photoinduced absorption band with clear vibronic structure, which we analyze rigorously using a time-dependent formalism of absorption to extract the principal excited-state vibrational normal-mode frequencies that couple to the electronic transition, the configurational displacement of the higher-lying excited state, and the reorganization energies. We can model the excited-state absorption spectrum using two totally symmetric vibrational modes with frequencies 450 (dimer) or 400 cm-1 (trimer), and 1666 cm-1. The reorganization energy of the ground-state absorption is rather insensitive to the oligomer length at 230 meV. However, that of the excited-state absorption evolves from 58 to 166 meV between the oligofluorene dimer and trimer. Based on previous theoretical work [A. Shukla, Phys. Rev. B 67, 245203 (2003)], we assign the absorption spectra to a transition from the 1 Bu excited state to a higher-lying m A g state, and find that the energy of the excited-state transition with respect to the ground-state transition energy is in excellent agreement with the theoretical predictions for both oligomers studied here. These results and analysis permit profound understanding of the nature of excited-state absorption in π -conjugated polymers, which are the subject of general interest as organic semiconductors in the solid state. © 2010 American Institute of Physics.en
dc.sourceJournal of Chemical Physicsen
dc.subjectOrganic polymersen
dc.subjectExcited statesen
dc.subjectAbsorption spectroscopyen
dc.subjectGround stateen
dc.subjectLight absorptionen
dc.subjectConjugated polymersen
dc.subjectGround state absorptionen
dc.subjectVibronic structureen
dc.subjectAbsorption spectraen
dc.subjectDilute solutionen
dc.subjectElectronic transitionen
dc.subjectExcited state absorptionen
dc.subjectNormal-mode frequenciesen
dc.subjectOligomer lengthen
dc.subjectOrganic semiconductoren
dc.subjectPhotoinduced absorptionen
dc.subjectReorganization energiesen
dc.subjectTheoretical predictionen
dc.subjectTotally symmetricen
dc.subjectTransient absorption spectraen
dc.subjectVibrational modesen
dc.titleAnalysis of the excited-state absorption spectral bandshape of oligofluorenesen
dc.description.issue21 Σχολή Θετικών και Εφαρμοσμένων Επιστημών / Faculty of Pure and Applied SciencesΤμήμα Χημείας / Department of Chemistry
dc.description.notes<p>Cited By :8</p>en
dc.contributor.orcidHayes, Sophia C. [0000-0002-2809-6193]

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