1. Laboratory of Advanced Optoelectronic MaterialsCollege of ChemistryChemical Engineering and Materials ScienceSoochow University Suzhou 215123 P.R. China
2. Department of Chemistry and Chemical EngineeringChalmers University of Technology Gothenburg 412 96 Sweden
3. Centro de Investigación en Materiales Avanzados S.C. (CIMAV)Unidad Monterrey Apodaca 66628 Mexico
4. Beijing National Laboratory for Molecular SciencesCAS Key Laboratory of Organic SolidsInstitute of ChemistryChinese Academy of Sciences Beijing 100190 P.R. China