[1] Shandong Normal Univ, Coll Phys & Elect, Jinan 250014, Peoples R China
[2] Shandong Univ, State Key Lab Crystal Mat, Jinan 250100, Peoples R China
[3] Chinese Acad Sci, Shanghai Inst Ceram, Key Lab Transparent & Optofunct Inorgan Mat, Shanghai 201800, Peoples R China