1. Stephenson Institute for Renewable Energy and Department of Physics, University of Liverpool, Liverpool L69 7ZF, U.K.
2. Institut für Physik and IRIS Adlershof, Humboldt-Universität zu Berlin, Berlin 12456, Germany
3. Paul-Drude-Institut fur Festkörperelektronik, Leibniz-Institut im Forschungsverbund Berlin e.V., Hausvogteiplatz 5-7, Berlin 10117, Germany
4. Institut für Festkörperphysik, Universität Bremen, Otto-Hahn-Allee 1, Bremen 28359, Germany
5. Institute of Experimental Physics I, Justus Liebig University Giessen, 35392 Giessen, Germany
6. Institute of Solid State Physics, Technische Universität Berlin, Hardenbergstr. 36, 10623 Berlin, Germany
7. School of Engineering, University of Liverpool, Brownlow Hill, Liverpool L69 3GH, U.K.
8. Department of Physics, Binghamton University, State University of New York, Binghamton, New York 13850, United States
9. Materials Science and Engineering, Binghamton University, State University of New York, Binghamton, New York 13850, United States
10. Diamond Light Source Ltd., Diamond House, Harwell Science and Innovation Campus, Didcot OX11 0DE, U.K.
11. Diamond Light Source Ltd., Harwell Science and Innovation Campus, Didcot OX11 0DE, U.K.
12. Lawrence Livermore National Laboratory, Livermore, California 94550, United States
13. Institut für Festkörpertheorie und -optik and European Theoretical Spectroscopy Facility, Friedrich-Schiller-Universität Jena, Max-Wien-Platz 1, D-07743 Jena, Germany
14. Department of Chemistry, University College London, 20 Gordon Street, London WC1H 0AJ, U.K.