[1] Peking Univ, Shenzhen Grad Sch, Shenzhen 518055, Guangdong, Peoples R China
[2] Peking Univ, Natl Key Lab Sci & Technol Micro Nano Fabricat, Beijing 100871, Peoples R China
[3] Chinese Acad Sci, State Key Lab Transducer Technol, Shanghai 200050, Peoples R China
[4] Innovat Ctr MicroNanoelect & Integrated Syst, Beijing 100871, Peoples R China