1. Shaanxi Key Laboratory for Advanced Energy Devices, Shaanxi Engineering Lab for Advanced Energy Technology, School of Materials Science and Engineering, Shaanxi Normal University, Shaanxi 710119, China
2. School of Physics, Northwest University, Shaanxi 710069, China
3. International Center for Materials Nanoarchitectonics, National Institute for Materials Science, 305-0044 1-1 Namiki, Tsukuba, Ibaraki 305-0044, Japan