1. State Key Laboratory of Molecular Engineering of Polymers, Department of Macromolecular Science Fudan University Shanghai 200438 China
2. Department of Chemistry, Advanced Research Institute, School of Chemical Science and Engineering Tongji University Shanghai 200092 China
3. Laboratory of Organic Electronics, Department of Science and Technology Linköping University 60174 Norrköping Sweden
4. Tomsk State University 36, Lenin Avenue 634050 Tomsk Russia
5. Department of Physics and Astronomy Uppsala University Box 516 SE-75120 Uppsala Sweden