1. CAS Center for Excellence in NanoscienceBeijing Key Laboratory of Micro‐Nano Energy and SensorBeijing Institute of Nanoenergy and NanosystemsChinese Academy of Sciences Beijing 100083 P. R. China
2. School of Nanoscience and TechnologyUniversity of Chinese Academy of Sciences Beijing 100049 P. R. China
3. Xinjiang Technical Institute of Physics & ChemistryChinese Academy of Sciences Urumqi Xinjiang 830011 P. R. China
4. Center on Nanoenergy ResearchSchool of Physical Science and TechnologyGuangxi University Nanning Guangxi 530004 P. R. China