Publication Type:Journal Article
Source:J. Phys. Chem. B, ACS Publications, Volume 117, Issue 16, p.4553-4559 (2013)
Keywords:2013, 2013 and earlier
We present two-dimensional Fourier transform optical spectroscopy measurements of two types of molecular J-aggregate thin films and show
that temperature-dependent dynamical effects govern exciton delocalization
at all temperatures, even in the presence of significant inhomogeneity.
Our results indicate that in the tested molecular aggregates, even when
the static structure disorder dominates exciton dephasing dynamics, the
extent of exciton delocalization may be limited by dynamical fluctuations,
mainly exciton-phonon coupling. Thus inhomogeneous dephasing may mediate
the exciton coherence time whereas dynamical fluctuations mediate the
exciton coherence length.