1. Joint Key Laboratory of the Ministry of Education Institute of Applied Physics and Materials EngineeringUniversity of Macau Macao SAR
2. State Key Discipline Laboratory of Wide-Bandgap Semiconductor Technologies School of MicroelectronicsXidian University Xi'an 710071 People's Republic of China
3. Hubei Key Laboratory of Ferro & piezoelectric Materials and Devices Faculty of Physics and Electronic ScienceHubei University Wuhan 430062 People's Republic of China