1. Electronic Materials Research Laboratory, Key Laboratory of the Ministry of Education and International Center for Dielectric Research, School of Electronic and Information Engineering, Xi'an Jiaotong University 1 , Xi'an 710049, Shaanxi, China
2. Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences 2 , Fuzhou 350002, Fujian, China
3. Fujian Science and Technology Innovation Laboratory for Optoelectronic Information of China 3 , Fuzhou 350108, Fujian, China
4. Department of Applied Physics, MOE Key Laboratory for Nonequilibrium Synthesis and Modulation of Condensed Matter, Xi'an Jiaotong University 4 , Xi'an 710049, Shaanxi, China