1. State Key Laboratory of Luminescent Materials and Devices; Institute of Optical Communication Materials; South China University of Technology; Guangzhou 510640 China
2. Beijing National Laboratory for Molecular Sciences; State Key Laboratory of Rare Earth Materials Chemistry and Applications; College of Chemistry and Molecular Engineering; Peking University; Beijing 100871 China
3. Shanghai Institute of Applied Physics; Chinese Academy Sciences; Shanghai Synchrotron Radiation Facility; Shanghai 201204 China
4. Otto Schott Institute of Materials Research; University of Jena; 07743 Jena Germany