1. State Key Laboratory of Metastable Materials Science & Technology and Key Laboratory for Microstructural Material Physics of Hebei Province, School of Science, Yanshan University, Qinhuangdao 066004, China
2. Centre for Advanced Optoelectronic Functional Materials Research and Key Laboratory for UV Light-Emitting Materials and Technology of Northeast Normal University, Changchun 130024, China
3. Key Laboratory of Functional Materials Physics and Chemistry of the Ministry of Education, College of Physics, and National Demonstration Center for Experimental Physics Education, Jilin Normal University, Changchun 130103, P. R. China