[1] Ningbo Univ, Sch Mat Sci & Chem Engn, Ningbo 315211, Peoples R China
[2] Chinese Acad Sci, Ningbo Inst Mat Technol & Engn, Ningbo 315201, Peoples R China
[3] Univ Chinese Acad Sci, Ctr Mat Sci & Optoelect Engn, Beijing 100049, Peoples R China
[4] Jiangsu Collaborat Innovat Ctr Photovolta Sci & En, Changzhou 213164, Peoples R China