1. Laboratory for Thin Films and Photovoltaics, Empa─Swiss Federal Laboratories for Materials Science and Technology, Überlandstrasse 129, CH-8600 Dübendorf, Switzerland
2. Laboratory of Inorganic Chemistry, Department of Chemistry and Applied Biosciences, ETH Zürich, Vladimir-Prelog-Weg 1, CH-8093 Zürich, Switzerland
3. Department of Materials Science and Engineering, University of Texas at Arlington, Arlington, Texas 76019, United States
4. Center for X-ray Analytics, Empa─Swiss Federal Laboratories for Materials Science & Technology, CH-8600 Dübendorf, Switzerland