1. Molecular Electronics, Zernike Institute for Advanced Materials, University of Groningen, Nijenborgh 4, 9747 AG Groningen, The Netherlands
2. Philips Research Laboratories, High Tech Campus 4, 5656 AE Eindhoven, The Netherlands
3. Eindhoven University of Technology, P.O. Box 513, 5600 MB Eindhoven, The Netherlands
4. Holst Centre/TNO, High Tech Campus 34, 5656 AE Eindhoven, The Netherlands
5. Enikolopov Institute of Synthetic Polymer Materials of Russian Academy of Sciences, Profsoyuznaya 70, 117393 Moscow, Russia
6. Institute of Solid State Physics, Graz University of Technology, Petersgasse 16A, 8010 Graz, Austria