1. Hunan Provincial Key Laboratory of Low‐Dimensional Structural Physics & Devices School of Physics and Electronics Hunan University Changsha 410082 China
2. Engineering Research Center of Advanced Semiconductor Technology and Application of Ministry of Education & Key Laboratory for Micro‐/Nano‐Optoelectronic Devices of Ministry of Education College of Semiconductors (College of Integrated Circuits) Hunan University Changsha 410082 China
3. State Key Laboratory for Chemo/Biosensing and Chemometrics College of Chemistry and Chemical Engineering Hunan Key Laboratory of Two‐Dimensional Materials Engineering Research Center of Advanced Catalysis of the Ministry of Education Hunan University Changsha 410082 China
4. Department of Materials Science and Engineering University of Washington Seattle WA 98195‐2120 USA
5. Changsha Semiconductor Technology and Application Innovation Research Institute College of Semiconductors (College of Integrated Circuits) Hunan University Changsha 410082 China
6. College of Materials Science and Engineering Hunan University Changsha Hunan 410082 China
7. State Key Laboratory of Disaster Prevention & Reduction for Power Grid (Hunan Electric Power Corporation Disaster Prevention and Reduction Center) Changsha 410007 China