1. Guangdong Provincial Key Laboratory of Optical Information Materials and Technology & Institute of Electronic Paper Displays South China Academy of Advanced Optoelectronics National Center for International Research on Green Optoelectronics South China Normal University Guangzhou 510006 P. R. China
2. Shenzhen Guohua Optoelectronics Tech. Co. Ltd Shenzhen 518110 P. R. China
3. Academy of Shenzhen Guohua Optoelectronics Shenzhen 518110 P. R. China
4. Van't Hoff Laboratory for Physical and Colloid Chemistry Debye Research Institute Utrecht University Padualaan 8 Utrecht 3584 CH Netherlands