title: Temporal full-colour tuning through non-steady-state upconversion.
abstract: Developing light-harvesting materials with tunable emission colours has always been at the forefront of colour display technologies. The variation in materials composition, phase and structure can provide a useful tool for producing a wide range of emission colours, but controlling the colour gamut in a material with a fixed composition remains a daunting challenge. Here, we demonstrate a convenient, versatile approach to dynamically fine-tuning emission in the full colour range from a new class of core-shell upconversion nanocrystals by adjusting the pulse width of infrared laser beams. Our mechanistic investigations suggest that the unprecedented colour tunability from these nanocrystals is governed by a non-steady-state upconversion process. These findings provide keen insights into controlling energy transfer in out-of-equilibrium optical processes, while offering the possibility for the construction of true three-dimensional, full-colour display systems with high spatial resolution and locally addressable colour gamut.
authors.affiliation: Department of Chemistry, National University of Singapore, Singapore 117543.
authors.forename: Renren
authors.initials: R
authors.lastname: Deng
authors.affiliation: Department of Electrical and Computer Engineering, National University of Singapore, Singapore 117583.
authors.forename: Fei
authors.initials: F
authors.lastname: Qin
authors.affiliation: Key Laboratory for Organic Electronics and Information Displays &Institute of Advanced Materials, Jiangsu National Synergistic Innovation Center for Advanced Materials, Nanjing University of Posts &Telecommunications, Nanjing 210023, China.
authors.forename: Runfeng
authors.initials: R
authors.lastname: Chen
authors.affiliation: 1] Key Laboratory for Organic Electronics and Information Displays &Institute of Advanced Materials, Jiangsu National Synergistic Innovation Center for Advanced Materials, Nanjing University of Posts &Telecommunications, Nanjing 210023, China [2] Key Laboratory of Flexible Electronics &Institute of Advanced Materials, Jiangsu National Synergistic Innovation Center for Advanced Materials, Nanjing Tech University, Nanjing 211816, China.
authors.forename: Wei
authors.initials: W
authors.lastname: Huang
authors.affiliation: Department of Electrical and Computer Engineering, National University of Singapore, Singapore 117583.
authors.forename: Minghui
authors.initials: M
authors.lastname: Hong
authors.affiliation: 1] Department of Chemistry, National University of Singapore, Singapore 117543 [2] Institute of Materials Research and Engineering, Agency for Science, Technology and Research, Singapore 117602.
authors.forename: Xiaogang
authors.identifier: 0000000325175790
authors.initials: X
authors.lastname: Liu