1. Institute
of Biomedicine and Biotechnology, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen 518055, P. R. China
2. Department
of Physics and Materials Science, City University of Hong Kong, Tat Chee
Avenue, Kowloon, Hong Kong, P.R. China
3. SZU-NUS
Collaborative Innovation Center for Optoelectronic Science and Technology,
and Key Laboratory of Optoelectronic Devices and Systems of Ministry
of Education and Guangdong Province, College of Optoelectronic Engineering, Shenzhen University, Shenzhen 518060, P. R. China