[1] Tsinghua Univ, Inst Nucl & New Energy Technol, Beijing 100084, Peoples R China
[2] Chinese Acad Sci, Beijing Inst Nanoenergy & Nanosyst, Beijing 100083, Peoples R China
[3] Univ Chinese Acad Sci, Sch Nanosci & Technol, Beijing 100049, Peoples R China
[4] Univ Sci & Technol Beijing, Sch Chem & Biol Engn, Beijing Key Lab Bioengineering & Sensing Technol, Res Ctr Bioengn & Sensing Technol, Beijing 100083, Peoples R China
[5] Univ Sci & Technol Beijing, Beijing Municipal Key Lab New Energy Mat & Techno, Beijing 100083, Peoples R China
[6] Tsinghua Univ, Fundamental Ind Training Ctr, Beijing 100084, Peoples R China
[7] Georgia Inst Technol, Sch Mat Sci & Engn, Atlanta, GA 30332 USA