1. Institute of Materials Research and Engineering Agency for Science, Technology and Research (A*STAR) 2 Fusionopolis Way Singapore 138634 Singapore
2. Division of Physics and Applied Physics School of Physical and Mathematical Sciences Nanyang Technological University Singapore 637371 Singapore
3. Centre for Disruptive Photonic Technologies The Photonics Institute Nanyang Technological University Singapore 637371 Singapore
4. School of Materials Science and Engineering Nanyang Technological University Singapore 639798 Singapore
5. ZJU‐Hangzhou Global Science and Technology Innovation Center Key Laboratory of Advanced Micro/Nano Electronic Devices & Smart Systems of Zhejiang Zhejiang University Hangzhou 311200 China
6. School of Electrical and Electronics Engineering Nanyang Technological University 50, Nanyang Avenue Singapore 639798 Singapore