1. Department of Materials Science and Engineering, and Centre for Functional Photonics (CFP) City University of Hong Kong Hong Kong SAR P. R. China
2. Division of Materials Physics Laboratory for Synthesis and Crystallography of Functional Materials Ruđer Bošković Institute Zagreb 10000 Croatia
3. Department of Physics The University of Hong Kong Hong Kong SAR P. R. China
4. Department of Chemistry The University of Hong Kong Hong Kong SAR P. R. China
5. SUSTech Academy for Advanced Interdisciplinary Studies Southern University of Science and Technology of China Shenzhen 518055 P. R. China