1. State Key Laboratory of Electronic Thin Films and Integrated Devices, University of Electronic Science and Technology of China, Chengdu 610054, China
2. School of Materials and Energy, Guangdong University of Technology, Guangzhou 510006, China
3. School of Electrical and Electronic Engineering, Nanyang Technological University, Singapore 639798, Singapore
4. School of Information and Software Engineering, University of Electronic Science and Technology of China, Chengdu 610054, China