Regensburg 2019 – wissenschaftliches Programm
Bereiche | Tage | Auswahl | Suche | Aktualisierungen | Downloads | Hilfe
CPP: Fachverband Chemische Physik und Polymerphysik
CPP 3: Molecular Electronics and Excited State Properties
CPP 3.3: Vortrag
Montag, 1. April 2019, 10:15–10:30, H13
Controlling Exciton Dynamics in Tetracene-Derivatives by Covalent Bounding of Two Chromophores — •Maximilian Frank1, Ulrich Müller1, Lena Roos2, Anke Krueger2, and Jens Pflaum1,3 — 1Experimental Physics VI, Julius Maximilian University of Würzburg, 97074 Würzburg — 2Institute of Organic Chemistry, Julius Maximilian University of Würzburg, 97074 Würzburg — 3ZAE Bayern, 97074 Würzburg
For an efficient operation of optoelectronic devices it is inevitable to control the photodynamics and, thus, the relevant loss channels like charge transfer formation or singlet fission (SF). In case of the latter, the excited singlet state decays into two triplet states of lower energy located on neighboring chromophores. Tetracene (Tc) is a model system to study this process and has motivated us to prove by rational design, here the covalent linking of two Tc chromophores, the effect of molecular packing on the optical properties and, in particular, on SF. By a comparative study on neat Tc and ditetracene (DTc) bulk crystals as well as anthracene crystals doped by the two entities at the single molecule level, different excitonic states can be identified together with the influence of the local environment and temperature. Quantities like spectral selective fluorescence lifetime, photoluminescence and absorption spectra as well as quantum efficiency are presented for each of the sample types studied, showing, as a key result, that SF is suppressed in DTc crystalline aggregates. Therefore, a model for the excitation energy landscape of DTc single crystals can be deduced and highlights the effect of the additional covalent bond on the photodynamics.