1. School of Materials Science and Engineering Nanyang Technological University 50 Nanyang Avenue Singapore 639798 Singapore
2. School of Electrical and Electronic Engineering Nanyang Technological University 50 Nanyang Avenue Singapore 639798 Singapore
3. Key Laboratory of Synthetic and Self‐Assembly Chemistry for Organic Functional Molecules Shanghai Institute of Organic Chemistry Chinese Academy of Sciences 345 Lingling Road Shanghai 200032 P. R. China
4. Department of Materials Science and Engineering City University of Hong Kong Tat Chee Avenue Kowloon Hong Kong SAR 999077 P. R. China
5. Center of Super‐Diamond and Advanced Films (COSDAF) City University of Hong Kong Tat Chee Avenue Kowloon Hong Kong SAR 999077 P. R. China