1. Institute for Molecules and Materials, Toernooiveld 1, 6525 ED, Nijmegen, The Netherlands, Applied Optics, University of Twente and MESA+ Institute for Nanotechnology, P.O. Box 217, 7500 AE Enschede, The Netherlands, Departament de Química, Universitat Autònoma de Barcelona, 08193 Cerdanyola del Vallès, Spain, Laboratory of Macromolecular and Organic Chemistry, Eindhoven University of Technology, P. O. Box 513, 5600 MB Eindhoven, The Netherlands, ICFO (Institut de Ciències Fotòniques), 08860...