1. Hubei Key Lab on Organic and Polymeric Optoelectronic MaterialsDepartment of ChemistryWuhan University Wuhan 430072 P. R. China
2. Shenzhen Key Laboratory of Polymer Science and TechnologyCollege of Materials Science and EngineeringShenzhen University Shenzhen 518060 P. R. China
3. School of ChemistryBeihang University Beijing 100191 P. R. China
4. Department of Chemistry and Hong Kong Branch of Chinese National Engineering Research Center for Tissue Restoration & ReconstructionHong Kong University of Science and Technology (HKUST) Clear Water Bay Kowloon Hong Kong 999077 P. R. China
5. Department of PhysicsChinese University of Hong Kong New Territories Hong Kong 999077 P. R. China