1. School of Electronic and Optical Engineering & College of MicroelectronicsNanjing University of Posts and Telecommunications Nanjing 210023 China
2. School of Electronic Science and EngineeringCollaborative Center of Advanced MicrostructuresNational Laboratory of Solid‐State MicrostructuresNanjing University Nanjing 210093 China
3. IMEP‐LAHCGrenoble‐INPMINATEC 3 Parvis Louis Neel, BP 257 Grenoble 38016 France
4. Key Laboratory of Polar Materials and DevicesMinistry of EducationDepartment of Electronic EngineeringEast China Normal University Shanghai 200241 China
5. Department of PhysicsNational Chung Hsing University Taichung 40227 Taiwan
6. Department of Chemical EngineeringPohang University of Science and Technology (POSTECH) 77 Cheongam‐Ro, Nam‐Gu Pohang 37673 Republic of Korea