1. School of Materials Sciences and EngineeringUniversity of Science and Technology Beijing Beijing 100083 P. R. China
2. Anhui Key Laboratory of Optoelectric Materials Science and TechnologyKey Laboratory of Functional Molecular SolidsMinistry of EducationAnhui Normal University Wuhu 241000 China
3. Laboratory of Crystal PhysicsKirensky Institute of PhysicsFederal Research Center KSC SB RAS Krasnoyarsk 660036 Russia
4. Siberian Federal University Krasnoyarsk 660041 Russia
5. Department of PhysicsFar Eastern State Transport University Khabarovsk 680021 Russia
6. National Synchrotron Radiation Research Center Hsinchu 300 Taiwan
7. State Key Laboratory of Luminescent Materials and Devices and Institute of Optical Communication MaterialsSouth China University of Technology Guangzhou 510641 China
8. Department of ChemistryNorthwestern University 2145 Sheridan Road Evanston IL 60208-3113 USA