1. Key Laboratory of Polar Materials and DevicesMinistry of EducationDepartment of Electronic EngineeringEast China Normal University Shanghai 200241 China
2. Department of Electrical Engineering and Institute of Electronic EngineeringNational Tsing Hua University Hsinchu 300 Taiwan
3. Department of Materials Science and EngineeringNational Chung Hsing University Taichung 40227 Taiwan
4. Department of ElectrophysicsNational Chiao Tung University Hsinchu 300 Taiwan
5. Graduate Institute of Applied Science and TechnologyNational Taiwan University of Science and Technology Taipei 106 Taiwan
6. Shanghai Institute of Intelligent Electronics & SystemsFundan University Shanghai 200433 China
7. Department of Physics and Institute of NanoscienceNational Chung Hsing University Taichung 40227 Taiwan
8. Research Center for Sustainable Energy and NanotechnologyInnovation and Development Center of Sustainable AgricultureNational Chung Hsing University Taichung 40227 Taiwan