1. Institutes of Physical Science and Information Technology, Anhui University, Hefei, Anhui 230601, China
2. Institute of Solid State Physics, Chinese Academy of Sciences, Hefei, Anhui 230031, China
3. Department of Chemistry, University of Science and Technology of China, Hefei, Anhui 230026, China
4. State Key Laboratory of Transducer Technology, Chinese Academy of Sciences, Hefei, Anhui 230031, China