1. CNR-IOM, Laboratorio TASC, Strada Statale 14, Km.163.5, I-34149 Trieste, Italy
2. Physics Department and CENMAT, University of Trieste, via A. Valerio 2, I-34127 Trieste, Italy
3. Department of Engineering, University of Cambridge, Cambridge CB3 0FA, United Kingdom
4. Helmholtz-Zentrum Berlin fuer Materialien und Energie GmbH, Division Solar Energy Research, Berlin 12489, Germany
5. Elettra–Sincrotrone S.C.p.A., Strada Statale 14, Km 163.5, I-34149 Trieste, Italy
6. Fritz Haber Institute, D-14195 Berlin-Dahlem, Germany