1. Institute for Advanced Materials, South China Academy of Advanced Optoelectronics and Guangdong Provincial Key Laboratory of Optical Information Materials and Technology, South China Normal University, Guangzhou 510006, China
2. Institute of Polymers and Energy Chemistry, College of Chemistry, Nanchang University, Nanchang 330031, China
3. Guangdong Provincial Key Laboratory of Optical Information Materials and Technology & Institute of Electronic Paper Displays, South China Academy of Advanced Optoelectronics, South China Normal University, Guangzhou 510006, China
4. Laboratory of Solid-State Microstructures, Nanjing University, Nanjing 210093, China
5. Department of Physics, Boston College, Chestnut Hill, Massachusetts 02467, United States