应用于白光LED上的掺杂量子点及其光稳定性研究

发布时间：2018-06-22 19:47

本文选题：胶体量子点 + 硫化镉　；参考：《东南大学》2015年硕士论文

【摘要】：最近几十年,半导体量子点越来越受到广泛的关注。与传统有机染料相比,量子点具有更宽的激发光谱、更窄的发射光谱、更大的斯托克斯位移以及更优良的光稳定性等。因此,它在光电方面以及生物学方面显示出了重要的应用前景和学术价值,是一类很有前途的纳米材料。本文的研究内容分为四个部分：第一部分用一锅法合成CdS:Mn/ZnS核壳掺杂结构的量子点；第二部分：在CdS:Mn/ZnS核壳掺杂结构的量子点表面包覆二氧化硅壳层；第三部分：CdS:Mn/ZnS核壳掺杂结构的量子点和CdS:Mn/ZnS@SiO2量子点的光稳定性研究；第四部分：CdS:Mn/ZnS核壳掺杂结构的量子点在白光LED中的应用研究。首先,采用一锅法合成了CdS:Mn/ZnS核壳掺杂结构的量子点,ZnS壳层从一层包覆至四层。通过透射电镜图谱表明合成的量子点颗粒大小均一、单分散性好、光学性质稳定,之后对其微观结构进行表征。然后,测量了室温下CdS:Mn/ZnS核壳掺杂结构的量子点的吸收谱、荧光光谱。结果表明,随着ZnS包层厚度的增加,吸收峰和发光峰发生轻微的红移,同时光致发光量子产率慢慢增大,在包覆两层时达到最高值。此外,我们通过W/O"反相微乳法”制备了CdS:Mn/ZnS@SiO2量子点,相比sol-gel方法(即Stober)反向微乳法包覆过程更为简单,所得到的二氧化硅纳米晶拥有更“光滑”的表面且更良好的单分散性,更重要的是,拥有非极性配体的量子点可以直接被包覆上。之后,我们对CdS:Mn/ZnS核壳掺杂结构的量子点和CdS:Mn/ZnS@SiO2量子点的光稳定性展开研究,探索氧气以及二氧化硅壳层对量子点稳定性的影响,并对测量结果给予了分析。最后,尝试用所合成的CdS:Mn/ZnS核壳掺杂结构的量子点应用在白光LED器件中并考察其各项性能。
[Abstract]:Semiconductor quantum dots have attracted more and more attention in recent decades. Compared with conventional organic dyes, quantum dots have wider excitation spectrum, narrower emission spectrum, larger Stokes shift and better light stability. Therefore, it has shown an important application prospect and academic value in optoelectronics and biology, and it is a kind of promising nano-materials. The content of this paper is divided into four parts: in the first part, CDs: mn / ZnS core-shell doped quantum dots are synthesized by one-pot method, the second part: coating silicon dioxide shell layer on the surface of CDs: mn / ZnS core-shell doped quantum dots; The third part is the study of the optical stability of the quantum dots with the structure of: CDs: mn / ZnS doped structure and the quantum dot of CdS: mn / ZnSSiO _ 2 doped structure, the fourth part is the application of the quantum dots doped with the structure of: CDs: mn / ZnS core-shell in white LED. Firstly, the ZnS shell layer of CdS: mn / ZnS core-shell doped structure was synthesized by one-pot method from one layer to four layers. Transmission electron microscopy (TEM) spectra showed that the synthesized QDs were homogeneous in size, monodisperse and stable in optical properties. The microstructure of the QDs was then characterized. Then, the absorption spectra and fluorescence spectra of CDs: mn / ZnS core-shell doped quantum dots at room temperature were measured. The results show that with the increase of ZnS cladding thickness, the absorption peak and luminescence peak show a slight red shift, and the photoluminescence quantum yield increases slowly, reaching the highest value when the two layers are coated. In addition, we prepared CDs: mn / ZnS- / Sio _ 2 quantum dots by "inverse microemulsion" method. Compared with sol-gel method, the coating process of ZnO nanocrystals is simpler than that of sol-gel method. The obtained silica nanocrystals have a more "smooth" surface and better monodispersity. More importantly, quantum dots with nonpolar ligands can be directly coated. After that, we study the optical stability of CDs: mn / ZnS core-shell doped quantum dots and CDs: mn / ZnSSiO _ 2 quantum dots, explore the effects of oxygen and silica shell layer on the stability of quantum dots, and analyze the measured results. Finally, the synthesized CDs: mn / ZnS core-shell doped quantum dots are applied to white LED devices and their properties are investigated.
【学位授予单位】：东南大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：O471.1

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