1. Institute
of Pharmaceutical Sciences, Department of Pharmaceutical Technology, Karl-Franzens Universität Graz, Universitätsplatz 1, 8010 Graz, Austria
2. Institute
of Solid State Physics, Graz University of Technology, Petersgasse
16, 8010 Graz, Austria
3. Institute
of Semiconductor and Solid State Physics, Johannes Kepler Universität Linz, Altenbergerstraße 69, 4040 Linz, Austria
4. Institute
of Solid State Physics, University of Bremen, Otto-Hahn-Allee 1, 28359 Bremen, Germany