Berlin 2012 – wissenschaftliches Programm
Bereiche | Tage | Auswahl | Suche | Aktualisierungen | Downloads | Hilfe
CPP: Fachverband Chemische Physik und Polymerphysik
CPP 24: Poster: Organic Semiconductors
CPP 24.8: Poster
Mittwoch, 28. März 2012, 11:00–13:00, Poster A
Characteristics of the excitonic processes in molecular donor/acceptor bilayers — •A.K. Topczak1, A. Steindamm1,2, M. Brendel1, P. Schütz1, and J. Pflaum1,2 — 1Exp. Phys. VI, Julius-Maximilians-University Würzburg, D-97074 Würzburg — 2ZAE Bayern e.V., D-97074 Würzburg
Knowledge of the exciton transport in molecular thin films is of great importance for organic photovoltaic (OPV) applications. We address this issue by Photoluminescence (PL)-Quenching measurements on the molecular semiconductor Diindenoperylene (DIP) in combination with different acceptor (C60, Phthalocyanine) and excitonic blocking (BPhen) materials both of relevance for OPV devices. This technique yields detailed information on the exciton diffusion length, which can be significantly enhanced for highly crystalline materials, and on the exciton dissociation probability at suited donor/acceptor interfaces. As will be demonstrated the latter strongly depends on the respective material combination in correlation with interface morphology and trap states. Furthermore, DIP-PL variation can be attributed to exciton dissociation, recombination or reflection at the respective interfaces. For the case of DIP/C60 bilayers, the dissociation efficiency amounts to 90% rendering recombination losses in this bilayer structure almost negligible. To further enhance charge carrier generation in DIP/C60 bilayer cells the impact of a BPhen exciton blocking layer was analysed via PL-measurements. By this approach effects by metal penetration and exciton reflection on exciton harvesting and therefore on the macroscopic device performance can be discriminated.