1. Center of Super‐Diamond and Advanced Films (COSDAF) and Department of Chemistry City University of Hong Kong Hong Kong SAR 999077 P. R. China
2. School of Materials Science and Engineering Hefei University of Technology Hefei Anhui 230009 P. R. China
3. Key Laboratory of Material Physics of Ministry of Education School of Physics and Microelectronics Zhengzhou University Zhengzhou 450052 P. R. China