1. Academy of Shenzhen Guohua Optoelectronics, Shenzhen 518110, P. R. China
2. Shenzhen Guohua Optoelectronics Tech. Co. Ltd, Shenzhen 518110, P. R. 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, P. R. China