双波长荧光发射量子点复合体系的构建及温度传感应用

Light-emitting quantum dots (QDs) have important applications in many special temperature monitoring of industrial environments. Based on bandgap engineering theory, the project aims to scientifically design composite system of QDs with dual-wavelength fluorescence emission, which can be applied in temperature sensor., The nucleus/interface layer/surface layer (quantum well/ barrier layer/quantum well) composite structure QDs can be synthesized by flexible chemical methods. Through regulation of the height and thickness of the interface barrier layer and electronic coupling degree between the nucleus and the surface layer, dual-wavelength fluorescence emission of QDs can be achieved. We will focus on the effects of the barrier layer and their energy level structure on the optical properties of the composite QDs. Based on the fluorescence thermosensitive difference of the intrinsic and doped semiconductor QDs, the ultra-sensitive, high-precision and visual temperature sensor can be realized by the signal output of the fluorescence ratio and color change of composite QDs. Researches on these key scientific issues will contribute for the practical realization of QDs.

发光量子点在许多特殊工业环境的温度监测中具有重要的应用价值。本项目旨在运用能带工程理论，科学地设计具有双波长荧光发射性质的量子点复合体系，并将其应用于可视化温度传感的研究。通过柔性的化学方法，合成晶核/界面层/表面层（量子阱/势垒层/量子阱）复合结构量子点，调控界面势垒层的高度和厚度，改变晶核与表面层之间的电子耦合程度，实现量子点双波长荧光发射，着重研究界面势垒层及其能级结构对复合结构量子点发光性质的影响。利用本征半导体量子点和掺杂量子点的荧光热敏性差异，通过比率荧光信号输出和颜色的改变，实现超灵敏、高精度和可视化温度传感。上述关键科学问题的研究，将为实现量子点的实用化作出贡献。

本项目利用能带工程理论，系统研究了双波长发光量子点的制备条件，并研究了掺杂浓度、掺杂时间、掺杂离子的种类等对量子点光学性质的影响。通过调控势垒层的厚度，改变晶核与表面层之间的电子耦合程度，实现Cu/Ag/Ni等双波长发光掺杂量子点的可控制备和CdSe/ZnS/CdSe、CdSe/CdS/CdSe双波长荧光发射，并通过变温光谱和变温寿命研究其光学性质，实现了可视化温度传感。另外，我们将II-VI族量子点拓展到钙钛矿量子点的研究，研究了杂质离子的种类、前驱体的活性、掺杂温度和浓度等实验条件的影响，并通过变温光谱研究其光学性质，构造了一种新型材料温度传感器。综上，我们较好地完成了申请书预期研究计划，并开拓了一些新型材料，为量子点的基础研究和广泛应用做出了贡献。