1. Linz Institute for Organic Solar Cells (LIOS), Physical Chemistry; Johannes Kepler University of Linz; 4040 Linz Austria
2. Laboratoire des Matériaux Organiques et Hétérochimie; Université de Tébessa; Algérie
3. Center for Surface and Nanoanalytics; Johannes Kepler University of Linz; 4040 Linz Austria
4. Istituto per la Sintesi Organica e la Fotoreattività; Consiglio Nazionale delle Ricerche; I-40129 Bologna Italy
5. Department of Physics; Indian Institute of Science; Bangalore 560012 India