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DS: Fachverband Dünne Schichten
DS 44: Postersession II
DS 44.9: Poster
Thursday, March 23, 2017, 17:00–19:00, P1C
Co-crystal formation and HOMO-LUMO coupling in mixtures of organic semiconductors. Diindenoperylene (DIP), sexithiophene (6T) as donors and hexafluorotetracyanonaphthoquinodimethane (F6TCNNQ) as acceptor. — •Giuliano Duva1, Paul Beyer2, Tino Meisel2, Andreas Opitz2, Alexander Hinderhofer1, Alexander Gerlach1, and Frank Schreiber1 — 1Universität Tübingen, Institut für Angewandte Physik, Auf der Morgenstelle 10, 72076 Tübingen (Germany) — 2Humboldt-Universität zu Berlin, Department of Physics, Berlin (Germany)
Donor:acceptor (D:A) blended films of organic semiconductors [1] represent a technologically relevant class of materials. Studying the structural and optical properties of the mixtures resulting upon co-evaporation is mandatory to control the parameters that govern the final performances of the device. Here we compare two D:A pairs, respectively DIP:F6TCNNQ and 6T:F6TCNNQ. We investigate their structure via X-ray scattering and find the formation of a D:A co-crystal exhibiting π-π stacking of the molecular components. Such structure correlates with the appearance of several new, sub-bandgap electronic transitions at energies specific for each combination. We discuss several models for charge-transfer, in particular a Hückel-like model for molecular orbitals [2], in order to relate the HOMO-LUMO energies of the compounds in the blend to the newly observed transitions. [1] A. Hinderhofer et al. Chem. Phys. Chem. 13 (2012), p.628. [2] H. Méndez et al. Angew. Chem. Int. Ed. 52 (2013), p.7751.