1. Institute of Applied Physics and Materials Engineering University of Macau Taipa Macao SAR 999078 China
2. Department of Electromechanical Engineering Faculty of Science and Technology University of Macau Taipa Macao SAR 999078 China
3. Shenzhen Key Laboratory of Polymer Science and Technology College of Materials Science and Engineering Shenzhen University Shenzhen 518060 P. R. China
4. Department of Physics and Chemistry Faculty of Science and Technology University of Macau Taipa Macao SAR 999078 China