1. Department
of Chemistry, National University of Singapore, 3 Science Drive 3, Singapore 117543, Singapore
2. Key
Laboratory of Flexible Electronics and Institute of Advanced Materials,
Jiangsu National Synergetic Innovation Center for Advanced Materials, Nanjing Tech University, Nanjing 211816, P. R. China
3. Key Laboratory for Organic Electronics and Information Displays & Institute of Advanced Materials, Jiangsu National Synergetic Innovation Center for Advanced Materials, Nanjing University of Posts and Telecommunications, Nanjing 210023, P. R. China
4. Luminescent
Materials Laboratory, DB, University of Verona, Strada Le Grazie
15, I-37134 Verona, Italy
5. Center
for Functional Materials, NUS Suzhou Research Institute, Suzhou, Jiangsu 215123, P. R. China