1. Max Planck Institute for Polymer Research, Ackermannweg 10, 55128 Mainz, Germany
2. Institute of Theoretical Physics and CMS, Vienna University of Technology, Wiedner Hauptstrasse 8-10, A-1040 Vienna, Austria
3. Bio-Organic Materials Chemistry Laboratory (BOMCLab), Institute of Electronic Structure and Laser, FORTH, 71110 Heraklion, Greece
4. Faculty of Physics, University of Vienna, Boltzmanngasse 5, A-1090 Vienna, Austria
5. Institute of Electronic Structure and Laser, FORTH, 71110 Heraklion, Greece
6. Department of Materials Science, University of Crete, 71110 Heraklion, Greece