1. Institute for Advanced Materials, South China Academy of Advanced Optoelectronics, South China Normal University, Guangzhou 510006, China
2. Guangdong Provincial Key Laboratory of Optical Information Materials, South China Academy of Advanced Optoelectronics, South China Normal University, Guangzhou 510006, China
3. Department of Applied Physics, The Hong Kong Polytechnic University, Hong Kong, China
4. National Center for International Research on Green Optoelectronics, South China Normal University, Guangzhou 510006, China
5. Laboratory of Solid State Microstructures and Innovation Center of Advanced Microstructures, Nanjing University, Nanjing 21009, China