1. Leibniz Institute for Solid State and Materials Research (IFW) Dresden; PO Box 270116 01171 Dresden Germany
2. Institute for Solid State Physics; Technische Universität Dresden; 01069 Dresden Germany
3. Adensis GmbH; Industriestraße 65 01129 Dresden Germany
4. Department of Chemistry, Faculty for Natural Sciences; Brandenburg Technical University Cottbus-Senftenberg; Großenhainer Str. 57 01968 Senftenberg Germany