1. Center on Nanoenergy Research School of Physical Science and Technology Guangxi University Nanning Guangxi 530004 P. R. China
2. CAS Center for Excellence in Nanoscience Beijing Key Laboratory of Micro‐Nano Energy and Sensor Beijing Institute of Nanoenergy and Nanosystems Chinese Academy of Sciences Beijing 101400 P. R. China
3. Beijing Key Laboratory of Printing and Packaging Materials and Technology Beijing Institute of Graphic Communication Beijing 102600 P. R. China
4. School of Nanoscience and Technology University of Chinese Academy of Sciences Beijing 100049 P. R. China
5. CUSPEA Institute of Technology Wenzhou Zhejiang 325024 P. R. China
6. School of Materials Science and Engineering Georgia Institute of Technology Atlanta GA 30332‐0245 USA