Department of Chemistry, National University of Singapore, Singapore 117543.
Department of Electrical and Computer Engineering, National University of Singapore, Singapore 117583.
Nat Nanotechnol. 2015 Mar;10(3):237-42. doi: 10.1038/nnano.2014.317. Epub 2015 Jan 19.
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.
开发具有可调发射颜色的光收集材料一直是色彩显示技术的前沿。材料组成、相和结构的变化可以为产生广泛的发射颜色提供有用的工具，但在具有固定组成的材料中控制色域仍然是一个艰巨的挑战。在这里，我们展示了一种通过调节红外激光束的脉冲宽度来动态微调全彩色范围内发射的便捷、通用的方法，这种方法适用于一类新型核壳上转换纳米晶体。我们的机理研究表明，这些纳米晶体前所未有的颜色可调性是由非稳态上转换过程控制的。这些发现为控制非平衡光学过程中的能量转移提供了深刻的见解，同时为构建具有高空间分辨率和局部可寻址色域的真正三维全彩色显示系统提供了可能性。
