1. State Key Laboratory of Luminescent Materials and Devices (SKLLMD) and Institute of Polymer Optoelectronic Materials and Devices; South China University of Technology (SCUT); Guangzhou 510640 China
2. Department of Physics; National University of Singapore; 3 Science Drive 2; and Department of Chemistry; National University of Singapore; 3 Science Drive 3 Singapore 117543
3. State Key Laboratory of Supramolecular Structure and Materials; Jilin University; 2699 Qianjin Avenue Changchun 130012 China
4. Department of Electrical and Electronic Engineering; The University of Hong Kong; Pokfulam Road Hong Kong China