1. Key Laboratory for the Physics and Chemistry of NanodevicesDepartment of ElectronicsPeking University Beijing 100871 China
2. National Key Laboratory of Science and Technology on Micro/Nano FabricationInstitute of MicroelectronicsPeking University Beijing 100871 China
3. Beijing Advanced Innovation Center for Materials Genome EngineeringBeijing Key Laboratory for Advanced Energy Materials and TechnologiesUniversity of Science and Technology Beijing Beijing 100083 China
4. Henan Key Laboratory of Diamond Optoelectronic Materials and DevicesKey Laboratory of Material PhysicsMinistry of EducationSchool of Physics and MicroelectronicsZhengzhou University Zhengzhou 450052 China