1. The
China-Germany Research Center for Photonic Materials and Device, The
State Key Laboratory of Luminescent Materials and Devices, School
of Materials Science and Engineering, South China University of Technology, Guangzhou 510640, P.R. China
2. Department
of Science and Environmental Studies, The Hong Kong Institute of Education, 10 Lo Ping Road, Tai Po. New Territories. Hong Kong S.A.R. P.R. China
3. College
of Sciences, Chongqing University of Posts and Telecommunications, Chongqing 400065, P.R. China
4. Institute
of Physics, University of Tartu, Ravila 14C, Tartu 50411, Estonia
5. Institute
of Physics, Jan Dlugosz University, Armii Krajowej 13/15, PL-42200 Czestochowa, Poland
6. Institute
of Physics, Polish Academy of Sciences, al. Lotnikow 32/46, 02-668 Warsaw, Poland