1. School of Materials Science and Engineering Nanyang Technological University Singapore 639798 Singapore
2. State Key Laboratory of Optoelectronic Materials and Technologies School of Materials Science and Engineering Sun Yat‐sen University Guangzhou 510275 China
3. Tim Taylor Department of Chemical Engineering Kansas State University Manhattan KS 66506 USA
4. Center for OptoElectronics and Biophotonics School of Electrical and Electronic Engineering and The Photonics Institute Nanyang Technological University Singapore 639798 Singapore
5. Department of Materials Science and Engineering National University of Singapore Singapore 117575 Singapore
6. School of Optoelectronic Science and Engineering University of Electronic Science and Technology of China Chengdu 611731 China
7. CINTRA CNRS/NTU/THALES UMI 3288, Research Techno Plaza Singapore 637553 Singapore