1. Photovoltaics and Thin-Film Electronics
Laboratory, Ecole Polytechnique Fédérale de Lausanne (EPFL), Institute of Microengineering (IMT), Rue de la Maladière 71B, Neuchâtel CH-2000, Switzerland
2. Department of Physics, University of Basel, Klingelbergstrasse 82, Basel CH-4056, Switzerland
3. Ernst Ruska—Centre for Microscopy and Spectroscopy with Electrons and Peter Grünberg Institute,
Forschungszentrum Jülich D-52425, Germany