1. Institute of Applied Physics and Materials Engineering, University of Macau, Macao 999078, P. R. China
2. Department of Materials Science and Engineering, Southern University of Science and Technology, Shenzhen 518055, P. R. China
3. Department of Physics and Chemistry, Faculty of Science and Technology, University of Macau, Macao 999078, P. R. China
4. Guangdong Provincial Key Laboratory of Computational Science and Material Design, Southern University of Science and Technology, Shenzhen 518055, P. R. China