1. Molecular Materials and Nanosystems, Eindhoven University of Technology, P.O. Box 513, 5600
MB Eindhoven, The Netherlands
2. Center of Electronics Optoelectronics
and Telecommunications (CEOT), Universidade do Algarve, Campus de Gambelas, 8005-139 Faro, Portugal
3. Philips Research Laboratories, Professor Holstlaan 4, 5656 AA Eindhoven,
The Netherlands