1. State Key Laboratory of Supramolecular Structure and Materials, College of Chemistry, Jilin University, Changchun 130012, P. R. China
2. State Key Laboratory of Superhard Materials, College of Physics, Jilin University, Changchun 130012, P. R. China
3. Department of Electronics, Xinzhou Teachers University, Xinzhou 034000, P. R. China
4. Department of Materials Physics and Chemistry, School of Materials Science and Engineering, Northeastern University, Shenyang 110819, P. R. China