1. College of Chemistry and Materials Science, Fujian Normal University, Fuzhou, Fujian 350007, P. R. China
2. Fujian Science & Technology Innovation Laboratory for Optoelectronic Information of China, Fuzhou, Fujian 350108, P. R. China
3. Key Laboratory of Design and Assembly of Functional Nanostructures, and Fujian Provincial Key Laboratory of Nanomaterials, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou, Fujian 350002, P. R. China
4. School of Physical Science University of Chinese Academy of Science, Beijing 100049, P. R. China