title: Relaxation dynamics and exciton energy transfer in the low-temperature phase of MEH-PPV.
abstract: Understanding the effects of aggregation on exciton relaxation and energy transfer is relevant to control photoinduced function in organic electronics and photovoltaics. Here, we explore the photoinduced dynamics in the low-temperature aggregated phase of a conjugated polymer by transient absorption and coherent electronic two-dimensional (2D) spectroscopy. Coherent 2D spectroscopy allows observing couplings among photoexcited states and discriminating band shifts from homogeneous broadening, additionally accessing the ultrafast dynamics at various excitation energies simultaneously with high spectral resolution. By combining the results of the two techniques, we differentiate between an initial exciton relaxation, which is not characterized by significant exciton mobility, and energy transport between different chromophores in the aggregate.
authors.affiliation: Institut für Physikalische und Theoretische Chemie, Universität Würzburg, Am Hubland, 97074 Würzburg, Germany.
authors.forename: Cristina
authors.initials: C
authors.lastname: Consani
authors.affiliation: Institut für Physikalische und Theoretische Chemie, Universität Würzburg, Am Hubland, 97074 Würzburg, Germany.
authors.forename: Federico
authors.initials: F
authors.lastname: Koch
authors.affiliation: Lehrstuhl Experimentalphysik II, Universität Bayreuth, Universitätsstraße 30, 95440 Bayreuth, Germany.
authors.forename: Fabian
authors.initials: F
authors.lastname: Panzer
authors.affiliation: Lehrstuhl Experimentalphysik II, Universität Bayreuth, Universitätsstraße 30, 95440 Bayreuth, Germany.
authors.forename: Thomas
authors.initials: T
authors.lastname: Unger
authors.affiliation: Lehrstuhl Experimentalphysik II, Universität Bayreuth, Universitätsstraße 30, 95440 Bayreuth, Germany.
authors.forename: Anna
authors.initials: A
authors.lastname: Köhler
authors.affiliation: Institut für Physikalische und Theoretische Chemie, Universität Würzburg, Am Hubland, 97074 Würzburg, Germany.
authors.forename: Tobias
authors.initials: T
authors.lastname: Brixner