1 Shenzhen Engineering Laboratory of Phosphorene and Optoelectronics, Key Laboratory of Optoelectronic Devices and Systems of Ministry of Education and Guangdong Province, College of Optoelectronic Engineering, Shenzhen University, Shenzhen 518060, China
2 Faculty of Information Technology, Macau University of Science and Technology, Macao, China
3 College of Chemistry and Environmental Engineering, Shenzhen University, Shenzhen 518060, China
4 School of Materials Science and Energy Engineering, Foshan University, Foshan 528000, China
5 e-mail: jiangxtemail@sina.com
6 e-mail: chenhongcs@126.com