1. Nanoelectronics, Institute of Electrical Engineering and Information Engineering, Kiel University, Kiel 24143, Germany
2. Institute for Materials Science − Synthesis and Real Structure, Faculty of Engineering, Kiel University, Kaiserstraße 2, Kiel D-24143, Germany
3. Kiel NanoSurface and Interface Science KiNSIS, Kiel University, Christian-Albrechts-Platz 4, Kiel D-24118, Germany
4. Ingram School of Engineering, Texas State University, San Marcos, Texas 78666, United States