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 Xi'an 710049 China
2. State Key Laboratory of Functional Materials for Informatics Shanghai Institute of Microsystem and Information Technology Chinese Academy of Sciences 865 Changning Road Shanghai 200050 China
3. Department of Chemistry and 4D LABS Simon Fraser University Burnaby British Columbia V5A 1S6 Canada
4. Department of Materials Science and Engineering University of California, Los Angeles Los Angeles CA 90095 USA