1. College of Electronic Science and Technology College of Optoelectronics Engineering SZU‐NUS Collaborative Innovation Centre for Optoelectronic Science & Technology, and Key Laboratory of Optoelectronic Devices and Systems of Ministry of Education and Guangdong Province Shenzhen University Shenzhen 518000 China
2. Department of Materials Science and Engineering Monash University Wellington Road Clayton Victoria 3800 Australia
3. Hunan Key Laboratory of Micro‐Nano Energy Materials and Devices and School of Physics and Optoelectronics Xiangtan University Hunan 411105 P. R. China
4. Division of Physics and Applied Physics School of Physical and Mathematical Sciences Nanyang Technological University Singapore 637371 Singapore
5. Department of Electrical and Computer Engineering National University of Singapore 4 Engineering Drive 3 Singapore 117583 Singapore