1. Department of Electrical and Electronic Engineering, Southern University of Science and Technology, Xueyuan Blvd. 1088, 518055 Shenzhen, China
2. Lehrstuhl für Funktionelle Materialien, Physik-Department, Technische Universität München, James-Franck-Straße 1, 85748 Garching, Germany
3. College of Engineering Physics, Shenzhen Technology University (SZTU), Lantian Road 3002, 518118 Shenzhen, China
4. College of New Materials and New Energies, Shenzhen Technology University (SZTU), Lantian Road 3002, 518118 Shenzhen, China
5. Department of Electrical and Electronic Engineering, The University of Hong Kong, Pokfulam Road, 999077 Hong Kong, China
6. Heinz Maier-Leibnitz-Zentrum (MLZ), Technische Universität München, Lichtenbergstr. 1, 85748 Garching, Germany