1. Faculty of Engineering, Institute for Materials Science, Christian-Albrechts Universität zu Kiel; Kaiserstr. 2 24143 Kiel Germany
2. Department of Microelectronics and Biomedical Engineering, Technical University of Moldova; Chisinau Republic of Moldova
3. Max-Planck-Institute for Solid State Research; Heisenbergstraße 1 70569 Stuttgart Germany