1. Empa, Swiss Federal Laboratories for Materials Science and Technology, Laboratory for Mechanics of Materials and Nanostructures, Thun 3602, Switzerland
2. Bern University of Applied Sciences, Institute for Applied Laser, Photonics and Surface Technologies ALPS, Biel/Bienne 2502, Switzerland
3. EPFL, École Polytechnique Fédérale de Lausanne, Laboratory for Photovoltaics and Thin Film Electronics, Neuchâtel 2000, Switzerland