1. School of Materials Science and EngineeringShanghai University Shanghai 200444 P. R. China
2. Advanced Nano‐materials DivisionSuzhou Institute of Nano‐Tech and Nano‐Bionics (SINANO)Chinese Academy of Sciences Suzhou 215123 P. R. China
3. Tianjin Key Laboratory of Molecular Optoelectronic SciencesDepartment of ChemistryInstitute of Molecular Aggregation ScienceTianjin University Tianjin 300072 P. R. China