1. Microsystem & Terahertz Research Center, China Academy of Engineering Physics, Chengdu 610200, China
2. Institute of Electronic Engineering, China Academy of Engineering Physics, Mianyang 621999, China
3. School of Electronics and Information Technology, State Key Lab of Opto-Electronic Materials & Technologies, Guangdong Province Key Lab of Display Materials and Technologies, Sun Yat-sen University, Guangzhou 510275, China