1. Department of Applied Physics, Eindhoven University of Technology, P.O. Box 513, 5600 MB Eindhoven, The Netherlands
2. NanoLab@TU/e, Eindhoven University of Technology, P.O. Box 513, 5600 MB Eindhoven, The Netherlands
3. Solliance Solar Research, High Tech Campus 5, 5656 AE Eindhoven, The Netherlands