1. School of Engineering College of Engineering and Computer Science The Australian National University Canberra ACT 2601 Australia
2. Institue of Electronic Materials and Devices Leibniz University Hannover 30167 Hannover Germany
3. Fraunhofer Institute for Solar Energy Systems ISE Heidenhofstr. 2 D-79110 Freiburg Germany
4. Centre for Microscopy, Characterization and Analysis The University of Western Australia Perth Western Australia 6009 Australia