1. Wuhan National Laboratory for Optoelectronics, School of Optical and Electronic Information, Huazhong University of Science and Technology, Wuhan 430074, China
2. Leibniz Institute of Surface Engineering (IOM), Permoserstr. 15, Leipzig 04318, Germany
3. Hubei Key Laboratory of Advanced Memories, Huazhong University of Science and Technology, Wuhan 430074, China
4. Laboratory of Infrared Materials and Devices, The Research Institute of Advanced Technologies, Ningbo University, Ningbo 315211, China