1. Joint Key Laboratory of the Ministry of Education Institute of Applied Physics and Materials EngineeringUniversity of Macau Macao SAR 999078 P. R. China
2. Department of Materials Science and EngineeringSouthern University of Science and Technology Shenzhen 518055, Guangdong P. R. China
3. Department of Physics and Chemistry Faculty of Science and TechnologyUniversity of Macau Macao SAR 999078 P. R. China