1. Institute of Electronic Devices; University of Wuppertal; Rainer-Gruenter-Str. 21 42119 Wuppertal Germany
2. Chair of Large Area Optoelectronics; University of Wuppertal; Rainer-Gruenter-Str. 21 42119 Wuppertal Germany
3. Nanograde AG; Laubisrütistrasse 50 8712 Stäfa Switzerland
4. RUBION, Ruhr-Universität Bochum; Universitätsstr. 150 44801 Bochum Germany
5. Surface Science Division; Institute of Materials Science; Darmstadt University of Technology; Petersenstraße 32 64287 Darmstadt Germany