1. Electronic Materials Research Laboratory, Key Laboratory of the Ministry of Education and International Center for Dielectric Research, School of Electronic Science and Engineering, Xi'an Jiaotong University 1 , Xi'an 710049, People’s Republic of China
2. Department of General Science, Sichuan University-Pittsburgh Institute, Sichuan University 2 , Chengdu, Sichuan 610065, People’s Republic of China
3. Department of Materials Science and Engineering, Sichuan University-Pittsburgh Institute, Sichuan University 3 , Chengdu, Sichuan 610065, People’s Republic of China