1. Institute of Electronic Devices and Wuppertal Center for Smart Materials & Systems University of Wuppertal 42119 Wuppertal Germany
2. Inorganic Materials Chemistry Ruhr University Bochum 44801 Bochum Germany
3. RUBION Ruhr University Bochum 44801 Bochum Germany
4. Carl Zeiss Microscopy GmbH 73447 Oberkochen Germany