1. Institute of Physics, University of Augsburg, 86135 Augsburg, Germany
2. Applied Organic Materials, Institute for High Frequency Technology, Technical University of Braunschweig, 38106 Braunschweig, Germany
3. Institute of Nanotechnology, Karlsruhe Institute of Technology, 76344 Eggenstein-Leopoldshafen, Germany
4. Merck KGaA, Performance Materials - Display Solutions, Frankfurter Straße 250, 64293 Darmstadt, Germany
5. Institute of Theoretical Informatics, Karlsruhe Institute of Technology, 76131 Karlsruhe, Germany