1. Key Laboratory of Advanced Technologies of Materials (Ministry of Education), School of Materials Science and Engineering, Southwest Jiaotong University, Chengdu 610031, PR China
2. College of Physics, Sichuan University, Chengdu 610065, PR China
3. School of Chemistry and Chemical Engineering, Southwest University, Chongqing 400715, PR China
4. School of Optoelectronic Engineering, Chengdu University of Information Technology, Chengdu 610225, PR China
5. Research Institute of Frontier Science, Southwest Jiaotong University, Chengdu 610031, PR China