[1] Chongqing Univ, Key Lab Optoelect Technol & Syst, Minist Educ, Int R&D Ctr Micronano Syst & New Mat Technol, Chongqing 400044, Peoples R China
[2] Chinese Acad Sci, Beijing Inst Nanoenergy & Nanosyst, Beijing Key Lab Micronano Energy & Sensor, CAS Ctr Excellence Nanosci, Beijing 100083, Peoples R China
[3] Chongqing Univ, State Key Lab Mech Transmiss, Chongqing 400044, Peoples R China
[4] Georgia Inst Technol, Sch Mat Sci & Engn, Atlanta, GA 30332 USA
[5] Univ Chinese Acad Sci, Sch Nanosci & Technol, Beijing 100049, Peoples R China
[6] Guangxi Univ, Sch Phys Sci & Technol, Ctr Nanoenergy Res, Nanning 530004, Guangxi, Peoples R China