[1] Chinese Acad Sci, Beijing Inst Nanoenergy & Nanosyst, Beijing 100083, Peoples R China
[2] Univ Chinese Acad Sci, Sch Nanosci & Technol, Beijing 100049, Peoples R China
[3] Chinese Acad Sci, Inst Semicond, Beijing 100083, Peoples R China
[4] Univ Sci & Technol Beijing, Res Ctr Bioengn & Sensing Technol, Beijing Key Lab Bioengn & Sensing Technol, Sch Chem & Biol Engn,Beijing Municipal Key Lab Ne, Beijing 100083, Peoples R China
[5] Univ Sci & Technol Beijing, Ctr Green Innovat, Sch Math & Phys, Beijing 100083, Peoples R China
[6] Georgia Inst Technol, Sch Mat Sci & Engn, Atlanta, GA 30332 USA