title: Exciton delocalization and superradiance in tetracene thin films and nanoaggregates.
abstract: The structure and dynamics of luminescent excitons in tetracene thin films and nanoaggregates are investigated using time-resolved spectroscopy and theoretical calculations. The orientation of tetracene's transition dipole moment along its short molecular axis leads to properties qualitatively different from those observed in aggregates of phenylene-vinylene and thiophene oligomers, despite similar crystal structures. The spectral shape, temperature dependence, and radiative lifetime are consistent with a short-lived superradiant exciton delocalized over approximately 10 tetracene molecules.
authors.affiliation: Department of Chemistry, University of Illinois, 600 South Mathews Avenue, Urbana, Illinois 61801, USA.
authors.forename: Sang-Hyun
authors.initials: SH
authors.lastname: Lim
authors.forename: Thomas G
authors.initials: TG
authors.lastname: Bjorklund
authors.forename: Frank C
authors.initials: FC
authors.lastname: Spano
authors.forename: Christopher J
authors.initials: CJ
authors.lastname: Bardeen