We demonstrate that the photoluminescence in nanocomposites composed of gradient CdSeS quantum dots (QD) doped in a host nematic liquid crystal (LC) can be substantially modulated due to photoisomerisation of small amounts of an incorporated azobenzene‐based LC material. An attractive feature of this reversible second‐wavelength optical control is that it can be achieved with low magnitude (0.6 mW/cm²) actinic UV light, and thus has very little scope for undesirable photooxidation. The modulation magnitude is high (45 %) and lends itself to both spatial and temporal control. The dynamics of the process for the forward (UV‐on) process is much faster than the return to the equilibrium situation. However, by applying a DC bias field we show that this return can be accelerated by a factor of more than 6, which under ideal circumstances could even be 20. This low‐power second‐wavelength on‐demand optical technique for emission modulation is generic and holds promises for the development of light‐switchable QD‐based emissive displays and photonic devices.

中文翻译：

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CdSeS梯度量子点/液晶纳米复合材料中的光致异构化驱动的光致发光调制。

我们证明，由于少量掺入的基于偶氮苯的LC材料的光异构化，可以基本上调节由掺杂在宿主向列液晶（LC）中的梯度CdSeS量子点（QD）组成的纳米复合材料中的光致发光。这种可逆的第二波长光学控制的一个吸引人的特点是可以实现低幅度（0.6 mW / cm ²）的光化紫外线，因此几乎没有发生不希望的光氧化的范围。调制幅度很高（45％），适合于空间和时间控制。正向（UV-on）过程的过程动力学比恢复到平衡状态要快得多。但是，通过施加DC偏置磁场，我们表明该返回速度可以加快6倍以上，在理想情况下甚至可以达到20。这种用于发射调制的低功率第二波长按需光学技术是通用的并有望开发基于光开关的QD发光显示器和光子器件。