1. School
of Materials and Energy, Guangdong University of Technology, Guangzhou 510006, China
2. Institute
of Polymer Optoelectronic Materials and Devices, State Key Laboratory
of Luminescent Materials and Devices, South China University of Technology, Guangzhou 510640, China
3. LUMINOUS!
Center of Excellence for Semiconductor Lighting and Displays, School
of Electrical and Electronic Engineering, Nanyang Technological University, Nanyang Avenue, 639798, Singapore