1. School of Physics, Shandong University, Jinan 250100, China
2. Division of Interfacial Water and Key Laboratory of Interfacial Physics and Technology, Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Shanghai 201800, People’s Republic of China
3. Shanghai Advanced Research Institute, Chinese Academy of Sciences, Shanghai 201210, China
4. School of Electronic Engineering, Chengdu Technological University, Chengdu 611730, China
5. Department of Chemistry, University of Nebraska-Lincoln, Lincoln, Nebraska 68588, USA