1. Department of Nanobiotechnology, Brandenburg University of Technology Cottbus-Senftenberg, 01968 Senftenberg, Germany
2. Department of Experimental Physics and Functional Materials, Brandenburg University of Technology Cottbus-Senftenberg, 03046 Cottbus, Germany
3. IHP—Leibniz Institut für Innovative Mikroelektronik, 15236 Frankfurt (Oder), Germany