Nanoskopische p-n-Grenzflächen aus Perylenbisimiden und Oligophenylenvinylenen durch hierarchische Selbstorganisation
Zusammenfassung der Projektergebnisse
The major objective of this project was the construction of mixed (two-component) dye aggregates from electron-donor oligo(p-phenylenevinylene)s (OPVs) and electron-acceptor perylene bisimides (PBIs) by the rational concept of hierarchical self-organization to achieve nanoscopic p-n-heterojunctions for potential application in solar cells. Toward this goal, numerous donor-acceptor-donor as well as donor-acceptor arrays of OPVs and PBIs were prepared by hydrogen-bond-directed self-assembly and covalent synthesis. Our detailed aggregation studies with these OPV-PBI arrays revealed that co-aggregates are formed by coself-assembly of OPV donor and PBI acceptor chromophores. Hydrogen-bonded OPV-PBI- OPV triads self-assemble into chiral stacks by pi-pi interactions. These aggregates show distinct changes in the UV/Vis absorption spectra, which could be conclusively ascribed to excitonic coupling between the chromophores of the same type. In addition, circular dichroism (CD) and atomic force microscopy (AFM) investigations demonstrated the formation of chiral aggregates at several hierarchical levels from nano- to the mesoscopic scale. Furthermore, transient absorption spectroscopic studies confirmed photoinduced electron transfer processes in co-aggregates of OPV-PBI arrays. Because the packing of the donor and acceptor dyes in these stacks is dependent on the individual components and their mode of connection (hydrogen-bonded or covalent), variations in charge separation and charge recombination rates are observed. With the hydrogen-bonded OPV-PBI-OPV complexes, fibers containing p-type and n-type organic semiconductors could be prepared on 1-20 nm scale. A photovoltaic device constructed by spin-coating a 100 nm thick layer of a hydrogenbonded OPV-PBI-OPV complex on a PEDOT:PSS-coated ITO substrate demonstrated that, in principle, the concept of this project is viable, although only poor diode behavior of this device was observed with an open circuit voltage of 0.74 V and a low current density (2.6 µA cm-2). The reason for the poor performance of this device is that the co-aggregated dyes tend to organize themselves laterally on the surface, which is not favorable for the charge transport to the electrodes. A more favorable orientation of the aggregates, i.e., perpendicular to the surface, may provide more efficient system. Long-term research activities will be required for the realization of such challenging objectives. On the other hand, these laterally oriented coaggregates showed notable ambipolar charge transport in field effect transistor devices which demonstrates the presence of percolation paths for electrons and holes as well.
Projektbezogene Publikationen (Auswahl)
- J. Am. Chem. Soc. 2004, 126, 10611–10618. Supramolecular p-n-Heterojunctions by Co-Self-Organization of Oligo(p-phenylene Vinylene) and Perylene Bisimide Dyes
F. Würthner, Z. Chen, F. J. M. Hoeben, P. Osswald, C.-C. You, P. Jonkheijm, J. van Herrikhuyzen, A. P. H. J. Schenning, P. P. A. M. van der Schoot, E. W. Meijer, E. H. A. Beckers, S. C. J. Meskers, R. A. J. Janssen
- J. Phys. Chem. A 2004, 108, 6933–6937. Charge Separation and Recombination in Photoexcited Oligo(p-phenylene vinylene): Perylene Bisimide Arrays Close to the Marcus Inverted Region
E. H. A. Beckers, S. C. J. Meskers, A. P. H. J. Schenning, Z. Chen, F. Würthner, R. A. J. Janssen
- BASF AG, Ludwigshafen, 7.12.2005, Kolloquium des Forschungsbereichs Wirk- und Effektstoffe: Supramolekulare Effektstoffe auf Basis selbstorganisierender Farbstoffe
- ChemPhysChem 2005, 6, 2389–2395. Scanning Tunneling Microscopy and Spectroscopy of Donor-Acceptor-Donor Triads at the Liquid/Solid Interface
H. Uji-i, A. Miura, A. Schenning, E. W. Meijer, Z. Chen, F. Würthner, F. C. De Schryver, M. Van der Auweraer, S. De Feyter
- International Conference MC7: Functional Materials for the 21st Century, Edinburgh, UK, 5.- 8. 7. 2005: Self-assembly of Perylene Bisimide Dyes into Photoluminescent and Semiconductive Nanostructures
- International Conference „Next Generations and Perspectives of Organic Chemistry“, Plenary lecture in Kyoto/Japan, 22. 3. 2005: Self-assembled Dye Architectures
- Org. Biomol. Chem. 2005, 3, 414–422. Hydrogen Bond Directed Self-Assembly of Core-Substituted Naphthalene Bisimides with Melamines in Solution and at the Graphite Interface
C. Thalacker, A. Miura, S. De Feyter, F. C. De Schryver, F. Würthner
- Org. Lett. 2005, 7, 967-670. Gelation of a Highly Fluorescent Urea-Functionalized Perylene Bisimide Dye
F. Würthner, B. Hanke, M. Lysetska, G. Lambright, G. S. Harms
- Universität Ulm, SFB 569 “Hierarchische Strukturbildung und Funktion organischanorganischer Nanosysteme“, 24.5.2005: Complex Dye Architectures by Hierarchical Selforganization
- 86th Annual Meeting of the Chemical Society of Japan, 30.3.2006, Funabashi/Tokyo, Plenarv lecture: Self-assembled Dye Architectures: Artificial Nanostructures Inspired by Nature
- Chem. Commun. 2006, 1188–1190. One-dimensional luminescent nanoaggregates of perylene bisimides
F. Würthner, Z. Chen, V. Dehm, V. Stepanenko
- GDCh-Vortrag, Universität Regensburg, 13.11.2006: Supramolekulare Farbenchemie: Funktionale Molekülverbände und Materialien
- GDCh-Vortrag, Wuppertal, 27.11.2006: Supramolekulare Farbenchemie: Funktionale Molekülverbände und Materialien
- J. Am. Chem. Soc. 2006, 128, 649–657. Influence of Intermolecular Orientation on the Photoinduced Charge Transfer Kinetics in Self-Assembled Aggregates of Donor-Acceptor Arrays
E. H. A. Beckers, S. C. J. Meskers, A. P. H. J. Schenning, Z. Chen, F. Würthner, P. Marsal, D. Beljonne, J. Cornil, R. A. J. Janssen
- J. Am. Chem. Soc. 2006, 128, 9535–9540. Control of Ambipolar Thin Film Architectures by Co-Self-Assembling Oligo(pphenylenevinylene)s and Perylene Bisimides
P. Jonkheijm, N. Stutzmann, Z. Chen, D. M. de Leeuw, E. W. Meijer, A. P. H. J. Schenning, F. Würthner
- J. Phys. Chem. B 2006, 110, 16967–16978. The Importance of Nanoscopic Ordering on the Kinetics of Photoinduced Charge Transfer in Aggregated ?-Conjugated Hydrogen-Bonded Donor-Acceptor Systems
E. H. A. Beckers, Z. Chen, S. C. J. Meskers, P. Jonkheijm, A. P. H. J. Schenning, X.-Q. Li, P. Osswald, F. Würthner, R. A. J. Janssen
- LMU München, Physik, BMO Seminar und SFB 533 Kolloquium, 21.11.2006: Self-assembly of Perylene Dyes into Photoluminescent and Semiconductive Nanostructures
- Lund, Schweden, 9.10.2006: Functional Dye Assemblies: Synthesis & Photophysical Processes
- Mons, Belgien, 25.10.2006, Vortrag: Energy and Electron Transfer Processes in Multichromophoric Perylene Bisimide Dye Arrays and Aggregates
- ORCHEM 2006, Tagung der Liebig-Vereinigung der GDCh in Bad Nauheim, 7.-9. 09.2006, Plenary lecture: Supramolecular Dye Chemistry: Functional Molecular Assemblies and Materials
- Org. Lett. 2006, 8, 3765–3768. Synthesis and Optical and Electrochemical Properties of Core-Fluorinated Perylene Bisimides
F. Würthner, P. Osswald, R. Schmidt, T. E. Kaiser, H. Mansikkamäki, M. Könemann
- University of Amsterdam, Van 't Hoff Institute for Molecular Sciences, 27.10.2006, John van Geuns Lecture: Supramolecular (Perylene) Dye Chemistry: Functional Molecular Assemblies and Materials
- University of Tokyo, 31.3.2006: Functional Merocyanine and Perylene Dye Assemblies and Materials
- XXI IUPAC Symposium on Photochemistry, Kyoto/Japan, 3.4.2006, invited lecture: Photoluminescent Arrays and Aggregates Based on Perylene Bisimide Dyes