1. Collaborative Innovation Center for Optoelectronic Science & Technology International Collaborative Laboratory of 2D Materials for Optoelectronics Science and Technology of Ministry of Education Institute of Microscale Optoelectronics Shenzhen University Shenzhen 518060 China
2. School of Chemistry and Chemical Engineering University of South China Hengyang 421001 China
3. Department of Physics and Astronomy Uppsala University Box 516 Uppsala SE‐751 20 Sweden