1. Key Laboratory for UV-Emitting Materials and Technology of Ministry of Education, Northeast Normal University, Changchun, 130024, China
2. State Key Laboratory of Luminescence and Applications, Changchun Institute of Optics, Fine Mechanics and Physics, Chinese Academy of Sciences, Changchun, 130033, China
3. Department of Physics, Georgia Southern University, Statesboro, GA, 30460, USA