[1] Tsinghua Univ, State Key Lab New Ceram & Fine Proc, Natl Ctr Elect Microscopy Beijing, Sch Mat Sci & Engn,Key Lab Adv Mat MOE, Beijing 100084, Peoples R China
[2] Chinese Acad Sci, Beijing Inst Nanoenergy & Nanosyst, Beijing, Peoples R China
[3] Tsinghua Univ, Ctr Nano & Micro Mech, Beijing 100084, Peoples R China
[4] Xiamen Univ, Res Inst Biomimet & So Matter, Xiamen 361005, Peoples R China
[5] Xiamen Univ, Dept Phys, Xiamen 361005, Peoples R China