飞秒激光流动烧蚀制备ZnSe有机复合量子点

发布时间：2018-01-17 19:33

本文关键词：飞秒激光流动烧蚀制备ZnSe有机复合量子点　出处：《激光与红外》2017年09期 　论文类型：期刊论文

【摘要】：采用飞秒激光流动烧蚀法制备了聚乙烯亚胺(PEI)包覆的ZnSe量子点水相分散液。水相分散液外观呈现亮黄色透明液体状。多个ZnSe有机复合量子点在水中聚集形成球形胶束,通过扫描电子显微镜(SEM)检测发现,胶束粒径为40~100 nm。利用高分辨透射电子显微镜(HRTEM)和X射线衍射(XRD)研究ZnSe晶体学特性变化,结果表明制得的ZnSe量子点保持了块体ZnSe的立方闪锌矿晶型。该ZnSe有机复合量子点的水分散液在365 nm紫外光照射下显示出明亮的绿色荧光,荧光中心波长约在500 nm处。采用光致发光光谱和紫外可见吸收光谱研究了该有机复合量子点的pH值响应特性,结果表明随着分散液中pH值由9降低到4,光致发光光谱显示出蓝移特性,波长最大蓝移量为25 nm。讨论了绿色荧光的来源与荧光波长调谐的可能机理。
[Abstract]:Polyethylene imine (PEI) was prepared by femtosecond laser flow ablation. The aqueous phase dispersion of coated ZnSe quantum dots. The appearance of aqueous phase dispersions is bright yellow transparent liquid. A number of ZnSe organic composite quantum dots gather in water to form spherical micelles. It was detected by scanning electron microscopy (SEM). The crystal properties of ZnSe were studied by means of high resolution transmission electron microscopy (HRTEM) and X-ray diffraction (XRD). The results show that the ZnSe quantum dots keep the cubic sphalerite crystal form of bulk ZnSe. The aqueous dispersion of the ZnSe organic composite quantum dots is obtained at 365. A bright green fluorescence was observed under UV light at nm. The photoluminescence spectra and UV-Vis absorption spectra were used to study the pH response of the organic composite quantum dots. The results show that the photoluminescence spectra show blue shift characteristics with the decrease of pH value from 9 to 4. The maximum blue shift is 25 nm. The source of green fluorescence and the possible mechanism of wavelength tuning are discussed.
【作者单位】：四川大学电子信息学院激光微纳工程研究所;华北光电技术研究所;
【基金】：国家自然科学基金项目(No.11574221)资助
【分类号】：O471.1;TN249
【正文快照】： 1引言荧光量子点材料在光发射器件[1]、光学显示[2]、微纳激光器[3]、光学探针[4-5]、光催化剂[6]、先进太阳能电池[7]和生物医学成像[8]等应用领域显示出了巨大的应用前景。通过控制粒径、成分组成、结构和外界温度等条件,现在已经能够对量子点的荧光波长进行有效的调节[7]。

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