1. The Henan Key Laboratory of Rare Earth Functional Materials
2. The Key Laboratory of Rare Earth Functional Materials and Applications
3. Zhoukou Normal University
4. Zhoukou 466001
5. P. R. China
6. College of Chemistry and Environmental Engineering
7. Pingdingshan University
8. Pingdingshan 467000
9. University Research Facility in Materials Characterization and Device Fabrication
10. The Hong Kong Polytechnic University
11. Hong Kong