1. Institute of Nanoscience and Nanotechnology, National Center for Scientific Research Demokritos, Agia Paraskevi, 15310 Athens, Greece
2. School of Applied Mathematical and Physical Sciences, National Technical University of Athens, Zografou Campus, 15780 Athens, Greece
3. Department of Chemistry, Aristotle University of Thessaloniki, 54124 Thessaloniki, Greece
4. Department of Chemistry, Laboratory of Bioinorganic Chemistry, University of Crete, Voutes Campus, Heraklion 70013, Crete, Greece
5. Cavendish Laboratory, University of Cambridge, CB3 0HE Cambridge, United Kingdom
6. Department of Physics, University of Ioannina, 45110 Ioannina, Greece
7. Solid State Physics Section, Physics Department, National and Kapodistrian University of Athens, Panepistimioupolis, 15784 Zografos, Athens, Greece
8. Theoretical and Physical Chemistry Institute, National Hellenic Research Foundation, Vas. Constantinou Avenue 48, 11635 Athens, Greece