1. Department of Physics, University of Konstanz, D-78457 Konstanz, Germany
2. IMEC Kapeldreef 75, Heverlee 3001, Belgium
3. 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, 00133 Rome, Italy
4. Department of Chemistry, Quaid-i-Azam University, Islamabad 45320, Pakistan
5. Department of Chemistry, University of Washington, Box 351700, Seattle, Washington 98195-1700, United States
6. Nanoscience and Technology Department, National Centre for Physics, Quaid-I-Azam University Campus, 44000 Islamabad, Pakistan
7. Institute of Advanced Materials (INAM). Universitat Jaume I, 12006 Castelló, Spain