1. Center for Programmable MaterialsSchool of Materials Science and EngineeringNanyang Technological University 50 Nanyang Avenue Singapore 639798 Singapore
2. Division of Physics and Applied PhysicsSchool of Physical and Mathematical SciencesNanyang Technological University Singapore 637371 Singapore
3. Department of ChemistrySchool of Science and Tianjin Key Laboratory of Molecular Optoelectronic ScienceTianjin University and Collaborative Innovation Center of Chemical Science and Engineering Tianjin 300072 China
4. School of Electrical and Electronic EngineeringNanyang Technological University Singapore 639798 Singapore
5. Beijing National Laboratory for Condensed Matter PhysicsInstitute of Physics, Chinese Academy of Sciences Beijing 100190 China
6. Institute of Materials Research and EngineeringA*STAR (Agency for Science, Technology and Research) 2 Fusionopolis Way, Innovis #08‐03 Singapore 138634 Singapore
7. Department of ChemistryCity University of Hong Kong Kowloon Hong Kong China hua.zhang@cityu.edu.hk