1. Centre for Hybrid and Organic Solar Energy (CHOSE); Department of Electronic Engineering; University of Rome - Tor Vergata; via del Politecnico 1 00133 Rome Italy
2. Department of Applied Physics; Eindhoven University of Technology; P. O. Box 513 5600 MB Eindhoven The Netherlands
3. Solar Research Solliance; High Tech Campus 21 5656 AE Eindhoven The Netherlands
4. Department of Chemical Science and Technologies; University of Rome “Tor Vergata,” Via della Ricerca Scientifica; 00133 Rome Italy