1. Department of Chemistry and INSTM, University of Pavia, Via Taramelli 16, Pavia 27100, Italy
2. Computational Laboratory for Hybrid/Organic Photovoltaics (CLHYO), Istituto CNR di Scienze e Tecnologie Chimiche “Giulio Natta” (CNR-SCITEC), Perugia 06123, Italy
3. Department of Physics, University of Pavia, Via Bassi 6, Pavia 27100, Italy
4. Department of Chemistry, Biology and Biotechnology, University of Perugia and INSTM, Perugia 06123, Italy
5. SKKU Institute of Energy Science and Technology (SIEST) Sungkyunkwan University, Suwon 440-746, Korea