1. Department of PhysicsNational University of Singapore 3, Science Drive 3 Singapore 117542 Singapore
2. Department of PhysicsIndian Institute of Technology Madras Chennai 600036 India
3. Department of ChemistryIndian Institute of Technology Kanpur Kanpur 208016 India
4. Department of ChemistryNational University of Singapore 3, Science Drive 3 Singapore 117542 Singapore
5. SZU‐NUS Collaborative Innovation Centre for Optoelectronic Science and TechnologyInternational Collaborative Laboratory of 2D Materials for Optoelectronic Science and Technology of Ministry of EducationCollege of Optoelectronic EngineeringShenzhen University Shenzhen Guangdong 518060 P. R. China