1. Jiangsu Key Laboratory for Carbon-Based Functional Materials & Devices, Institute of Functional Nano & Soft Materials (FUNSOM) Soochow University Suzhou, Jiangsu 215123 P. R. China
2. School of Physics and Electronic Science East China Normal University Shanghai 200062 P. R. China
3. Macao Institute of Materials Science and Engineering (MIMSE) Faculty of Innovation Engineering Macau University of Science and Technology Taipa, Macao 999078 P. R. China
4. Guangzhou New Vision Opto-Electronic Technology Co., Ltd. Guangzhou, Guangdong 510730 P. R. China