1. Key Laboratory of Materials Physics and Anhui Key Laboratory of Nanomaterials and NanotechnologyInstitute of Solid State Physics, Hefei Institutes of Physical ScienceChinese Academy of Sciences Hefei 230031 China
2. University of Science and Technology of China Hefei 230026 China
3. College of Physics and Materials ScienceHenan Normal University Xinxiang Henan 453007 China
4. College of Electronic Information and Optical EngineeringNankai University Tianjin 300350 China
5. Shandong University of Science and TechnologyCollege of Chemical and Environmental Engineering Qingdao Shandong 266510 China