1. Department of Chemistry and the Materials Research Center, Northwestern University, 2145 Sheridan Road, Evanston, Illinois 60208, United States
2. Department of Materials Science and Engineering and the Materials Research Center, Northwestern University, Evanston, Illinois 60208, United States
3. School of Automation Engineering, University of Electronic Science and Technology of China (UESTC), Chengdu, Sichuan 611731, China
4. Department of Physics, Missouri University of Science and Technology, Rolla, Missouri 65409, United States
5. Flexterra Inc., 8025 Lamon Avenue, Skokie, Illinois 60077, United States