1. College of Chemistry and Environmental Engineering Shenzhen University Shenzhen Guangdong 518060 P. R. China
2. College of Physics and Optoelectronic Engineering Shenzhen University Shenzhen Guangdong 518060 P. R. China
3. Department of Mechanical and Materials Engineering University of Western Ontario London Ontario N6A 5B9 Canada
4. Department of Materials Science and Engineering Southern University of Science and 13 Technology Shenzhen 518055 China