[1] Univ Sci & Technol China, Sch Microelect, Hefei 230026, Peoples R China
[2] Univ Sci & Technol China, Natl Synchrotron Radiat Lab, Hefei 230029, Peoples R China
[3] Univ Sci & Technol China, CAS Key Lab Microscale Magnet Resonance, Hefei 230026, Peoples R China
[4] Univ Sci & Technol China, Sch Phys Sci, Hefei 230026, Peoples R China
[5] Lawrence Berkeley Natl Lab, Mat Sci Div, Berkeley, CA 94720 USA
[6] Univ Massachusetts, Polymer Sci & Engn Dept, Amherst, MA 01003 USA
[7] Lawrence Berkeley Natl Lab, Adv Light Source, Berkeley, CA 94720 USA
[8] Univ Sci & Technol China, Collaborat Innovat Ctr Chem Energy Mat iChEM, Dept Mat Sci & Engn, Key Lab Precis & Intelligent Chem, Hefei 230026, Peoples R China