1. Laboratory of Optics and Molecular Materials, Department of Engineering Physics and Mathematics and Center for New Materials, Helsinki University of Technology, P.O. Box 2200, FIN-02015 HUT, Espoo, Finland, STFI-Packforsk AB, P.O. Box 5604, SE-114 86 Stockholm, Sweden, Department of Fibre and Polymer Technology, Royal Institute of Technology, KTH, Stockholm, Sweden, Molecular Electronics and Nanotechnology, Physics Department, SNIAM Building, Trinity College, Dublin, Ireland, and Laboratory of Forest...