[1] Fraunhofer Institute for Solar Energy Systems (ISE), Heidenhofstrasse 2, 79110 Freiburg, Germany
[2] Department of Engineering, College of Engineering and Computer Science, Australian National University, Canberra, ACT 0200, Australia
[3] Lehrstuhl für Angewandte Physik (LAP), University of Erlangen Nürnberg, 91058 Erlangen, Germany
[4] Q-Cells AG, Thalheim, Germany