1. Workgroup Emerging Solar Cell Technologies Institute for Solar Energy Research Hamelin (ISFH) Am Ohrberg 1 Emmerthal 31860 Germany
2. Institute of Electronic Materials and Devices Leibniz Universität Hannover Schneiderberg 32 Hannover 30167 Germany
3. Institute for Solid State Physics Leibniz Universität Hannover Appelstraße 2 Hannover 30167 Germany