1. C.H.O.S.E. (Centre for Hybrid and Organic
Solar Energy), Department of Electronic Engineering, University of Rome “Tor Vergata”, via del Politecnico 1, Rome 00133, Italy
2. Research
Center in the Physics of Matter and Radiation (PMR), Laboratoire Interdisciplinaire
de Spectroscopie Electronique (LISE), University of Namur, B-5000 Namur, Belgium
3. Department of Materials Science & Metallurgy, University of Cambridge, 27 Charles Babbage road, CB3 0FS, Cambridge, U.K.