1. College of Chemistry and Chemical Engineering, Henan University, Kaifeng 475004, Henan, P. R. China
2. Laboratory of Organic Electronics, Department of Science and Technology, Linköping University, Norrköping SE-60174, Sweden
3. Department of Chemistry, Faculty of Science, University of Helsinki, FIN-00014 Helsinki, Finland
4. Department of Optics and Spectroscopy, Tomsk State University, Tomsk 634050, Russia
5. Department of Chemistry, University of Copenhagen, Copenhagen Ø DK-2100, Denmark
6. Department of Physics and Astronomy, Uppsala University, Uppsala SE-75120, Sweden