1. Key Laboratory of Radiation Physics and Technology of Ministry of Education, Institute of Nuclear Science and Technology, Sichuan University, Chengdu 610064, People's Republic of China
2. Shenzhen Institutes of Advanced Technology Chinese Academy of Sciences, Shenzhen 518055, People's Republic of China
3. The Chinese University of Hong Kong, Hong Kong, People's Republic of China
4. Institut d'Electronique Fondamentale, CNRS-Université Paris Sud UMR 8622, 91405 Orsay, France