掺杂ZnS纳米晶的合成及其性能研究

发布时间：2018-01-20 11:15

  本文关键词： ZnS纳米晶 离子液体 掺杂离子 荧光　出处：《河南科技大学》2015年硕士论文　论文类型：学位论文

【摘要】：半导体纳米晶由于量子限域效应,导致具有特殊的光电性能,使其应用领域越来越广泛,尤其在生物分子标记领域体现出了潜在的应用价值。目前,用作生物标记的量子点主要是CdSe、CdS、CdS/Zn S(Zn Se)、Cd Te/ZnS等体系,但都含有Cd元素,其毒性一直是人们担心的问题。ZnS是一种宽带隙II-VI族半导体材料,是一种良好的掺杂基质,掺杂后可以得到不同波段的、发光效率高的半导体纳米晶,有望成为新型、高灵敏的荧光标记物。本文以1-乙基-3-甲基咪唑四氟硼酸盐离子液体和水的混合溶液作为反应溶剂,采用溶剂热法合成了不同离子掺杂的ZnS纳米晶。通过X射线衍射仪(XRD)、X光电子能谱仪(XPS)、透射电镜(TEM)研究其物相、相貌和尺寸;结合F-280荧光分光光度谱仪和Zolix SBP-300型光栅光谱仪研究纳米晶的光学性能。研究结果如下:1.ZnS纳米晶(掺杂离子为Cu,Fe,Er,Yb)颗粒近似呈球形,粒度约3-10nm,部分粉体出现少量的团聚现象;选区衍射中的电子衍射环表明合成的Zn S纳米晶为多晶结构。2.Cu、Fe、Er、Yb掺杂离子分别以Cu+/Cu2+、Fe2+、Er3+、Yb3+形式掺杂到ZnS纳米晶中;Fe离子掺杂后,增加了Cu2+在ZnS纳米晶中的含量;Yb离子掺杂后,增加了Er3+在ZnS纳米晶中的含量。3.ZnS:Cu纳米晶有两个较强的发射峰分别位于425nm和468nm处。200℃时,Cu2+离子掺杂量为2%时,ZnS:Cu纳米晶发光强度达到最强。Fe掺杂后,Zn S:Cu纳米晶的荧光峰强度增加;反应温度为140℃,反应时间为10h,掺杂量为2%的Cu/Fe的ZnS纳米晶荧光性能最好。4.Zn S:Er纳米晶在420nm,470nm和530nm处出现了新的发光峰。反应温度为120℃,反应时间为10h,掺杂量为2%的ZnS:Er纳米晶荧光性能最好;140℃时,反应时间为8h和10h时,均当掺杂浓度为2%时,Zn S:Er/Yb纳米晶荧光强度达到最强。5.采用980nm、200mW激光器对ZnS:Er/Yb纳米晶进行激发,获得了4f-4f轨道电子的上转换发光,出现了540nm(绿色)和655nm(橙红色)两个荧光峰。本文通过Cu、Fe、Er、Yb离子的掺杂,获得激发光和发射光可调的无镉半导体ZnS纳米晶,有望将其应用于发光器件和生物标记领域。
[Abstract]:Semiconductor nanocrystals have special optoelectronic properties due to the quantum limiting effect, which makes their applications more and more extensive, especially in the field of biomolecules. The quantum dots used as biomarkers are mainly CdSee / CDs / ZnSU / ZnSee / CD Te/ZnS systems, but all of them contain CD elements. Its toxicity has always been a concern. ZnS is a wide band gap II-VI semiconductor materials, is a good doped substrate, doping can be obtained in different bands. Semiconductor nanocrystalline with high luminescence efficiency is expected to be a new and highly sensitive fluorescent marker. In this paper, the mixed solution of 1-ethyl-3-methylimidazolium tetrafluoroborate ionic liquid and water is used as the reaction solvent. ZnS nanocrystals doped with different ions were synthesized by solvothermal method. The phase of ZnS nanocrystals was studied by X-ray diffractometer X-ray photoelectron spectroscopy (XPS) and transmission electron microscopy (TEM). Appearance and size; The optical properties of nanocrystals were studied by F-280 fluorescence spectrometer and Zolix SBP-300 grating spectrometer. The results are as follows: 1. ZnS nanocrystalline (doped ion is Cu). The particle size is about 3-10 nm, and a small amount of agglomeration occurs in some of the powders. The electron diffraction ring in the selected area diffraction shows that the synthesized ZnS nanocrystals are polycrystalline structure. 2. The doped ions of Cu / Cu ~ (2 +) and Fe _ (2) O _ (2) er _ (3) respectively. Yb3 was doped into ZnS nanocrystals. Fe ion doping increased the content of Cu2 in ZnS nanocrystals. Yb ion doping increases the content of Er3 in ZnS nanocrystals. 3. There are two strong emission peaks of ZnS: cu nanocrystals at 425nm and 468nm at .200 鈩，

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