1. School of Physical Science and Technology Lanzhou University Lanzhou 730000 China
2. Department of Physics and Beijing Key Laboratory of Energy Conversion and Storage Materials Beijing Normal University Beijing 100084 China
3. School of Materials and Energy Lanzhou University Lanzhou 730000 China
4. Department of Mechanical Engineering City University of Hong Kong 83 Tat Chee Avenue Kowloon Hong Kong
5. Department of Chemistry, Faculty of Science King Khalid University Abha 61413 Saudi Arabia
6. Key Laboratory of Luminescence Analysis and Molecular Sensing, Ministry of Education, School of Materials and Energy Southwest University Chongqing 400715 P. R. China