共查询到19条相似文献,搜索用时 875 毫秒
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用溶剂热法合成Yb3+、Er3+共掺的NaYF4 纳米上转换材料, 研究了去离子水、乙醇两种反应溶剂对材料性能的影响. 用X射线衍射光谱、扫描电镜和荧光光谱等测试手段对材料性能进行了对比分析. 结果表明: 以乙醇为溶剂并加入一定比例的EDTA, 所制备的上转换材料能发射较强的、可被太阳电池吸收的可见光. 相似文献
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简要概述了现有的纳米石墨制备方法,这些方法从材料来源上可以分为2类,一类由鳞片石墨来制备,另一类由富碳材料合成.由鳞片石墨制备纳米石墨的方法主要有球磨法、超声波粉碎法、爆轰裂解法和电化学插层法;由富碳材料合成纳米石墨的方法主要包括爆轰合成法、化学气相沉积法、激光脉冲沉积法和化学合成法. 相似文献
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采用水溶性聚合物聚乙烯亚胺(PEI)调介下的水热法,一步合成了具有纤维状中空结构的六方相NaYF4:Yb3+,Er3+上转换荧光材料,并将其作为荧光填料,通过流延成膜法制备了具有上转换荧光性能的壳聚糖/聚乙烯醇(CS/PVA)荧光复合薄膜.探究了PEI配体含量和反应体系pH值对合成的上转换材料的形貌、晶型和荧光性能的影响,以及壳聚糖/聚乙烯醇荧光复合薄膜中荧光填料的最佳掺杂量.研究结果表明,在PEI含量为0.3 g且反应体系pH=5的条件下,合成的产物为具有纤维状中空结构的六方相NaYF4:Yb3+,Er3+.荧光光谱表明,合成的NaYF4:Yb3+,Er3+上转换材料在980 nm激光激发下具有优异的荧光性能.当荧光填料的掺杂质量分数为3.0%时,制备的NaYF4:Yb3+,Er3+/(CS/PVA)荧光复合薄膜具有最佳的透明度和上转换荧光特性. 相似文献
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采用溶胶-凝胶法在水相合成了纳米NaYF_4:Er~(3 ),Yb~(3 )上转换材料,980nm红外激光照射下,肉眼可观察到明亮的上转换发光。实验研究了铒、镱掺杂浓度及焙烧温度对材料合成的影响。所合成的纳米材料呈圆球形、颗粒均匀、分散性好,平均粒径70nm,可应用于生物标记。 相似文献
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燃烧合成法制备IP板荧光粉工艺参数的研究 总被引:2,自引:0,他引:2
涂在IP板(Imaging Plate,简称IP)上的荧光粉BaFBrEu2+可存储X线影像,并通过光激励发光读出存储的光信息.BaFBrEu2+传统的制备方法是高温固相法,而燃烧合成法一直应用在合成金属氧化物和难熔金属之间的合成上,用这种方法制备不含氧的化合物还未见报道.本文报道了如何利用燃烧合成法制备IP板荧光粉一种不含氧的化合物,着重讨论了燃烧合成法的工艺对材料的结构和性能的影响. 相似文献
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Lu Q Hou Y Tang A Feng Z Teng F Liu X 《Journal of nanoscience and nanotechnology》2011,11(11):9671-9675
Y2O3:Er3+ upconversion materials with nanoporous structures were prepared by a hydrothermal method following a post-thermal treatment. The structure and morphology of the materials were characterized by X-ray diffraction (XRD) and field-emission scanning electron microscopy (FESEM). The results indicated that the as-obtained Y2O3:Er3+ powders were of cubic-phase structure, and the nanoporous structure was formed in the annealing process. The optical results indicated that high annealing temperature could improve the upconversion properties, but it could destroy the nanoporous structure. Under 980 nm excitation, red (4F(9/2) --> 4I(15/2) and green (2H(11/2), 4S(3/2) --> 4I(15/2)) upconversion luminescence was observed. The studies on the intensity dependence of upconversion emission indicated that two-photon processes were responsible for the green and red upconversion luminescence. This kind of multifunctional material has potential applications in nanocontainers for use as biomolecule and drugs carriers. 相似文献
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Hexagonal-phase NaYF(4):Yb, Er/Tm nanocrystals are the best IR-to-visible upconverting materials to date, but user-friendly methods for making pure hexagonal-phase NaYF(4):Yb, Er/Tm nanocrystals with upconversion fluorescence are still lacking. Most of the methods reported so far require excess fluoride reactants in a high-temperature reaction which are very unfriendly to users and raise safety concerns. In this work, an efficient and user-friendly method was developed for the synthesis of uniform hexagonal-phase NaYF(4):Yb, Er/Tm nanocrystals with upconversion fluorescence, by forming small solid-state crystal nuclei and further growth and ripening of the nuclei. NaYF(4):Yb, Er/Tm nanoplates, nanospheres and nanoellipses were also selectively produced by varying the concentration of the surfactant. All the nanocrystals showed strong upconversion fluorescence, and fluorescence from the nanoplates was observed even when the laser power density was reduced to about 50?mW?cm(-2). These nanocrystals have great potential for use in biology and medicine as fluorescent labels or imaging probes. 相似文献
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针对N719染料仅可吸收可见光这一局限,本研究旨在通过引入上转换发光材料并将其应用于染料敏化太阳能电池的光阳极来拓宽光谱吸收范围,提高光的捕获率,进而达到提高电池光电转换效率的目的。首先,采用水热合成法以不同pH值的先驱体溶液,成功制备了Yb~(3+)/Er~(3+)双掺杂La(OH)_3粉末,然后将适量合成的稀土发光粉掺入TiO_2纳米浆料中,采用刮涂法成膜制备光阳极,并将其组装成染料敏化太阳能电池。研究结果表明,稀土发光粉的加入拓宽了光谱吸收范围,在其掺杂量达到3%时,电池的短路电流密度Jsc提高到17.72mA·cm-2,最终获得了8.3%的光电转换效率。 相似文献
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Hu Haisheng Jiang Qun Li Yunfei Liu Meitang 《Journal of Materials Science: Materials in Electronics》2022,33(2):596-606
Journal of Materials Science: Materials in Electronics - The K+-doped (Na1?xKx)GdF4:Er3+,Yb3+ upconversion materials were successfully synthesized by solvothermal method. The doping of K+ was... 相似文献
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Hedgehog‐Like Upconversion Crystals: Controlled Growth and Molecular Sensing at Single‐Particle Level 下载免费PDF全文
Xiaowang Liu Xiyan Li Xian Qin Xiaoji Xie Ling Huang Xiaogang Liu 《Advanced materials (Deerfield Beach, Fla.)》2017,29(37)
Topological control of nanostructures plays a crucial role in understanding the crystal growth process at the nanometer length scale. Here, the scalable synthesis of upconversion materials with distinct hedgehog‐like morphologies by a seed‐mediated synthetic procedure is reported. It is demonstrated that a close match in the crystal lattice between the core and shell components is essential for synthesizing such hierarchical nanostructures. These optical nanomaterials also enable the development of a single‐particle‐based platform for high‐sensitivity molecular sensing. 相似文献
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目的 从增强稀土离子发光的角度考察上转换发光调控及性能,综述稀土发光材料在光学防伪领域的应用,以期为上转换材料与包装材料的功能化研究提供参考。方法 检索近几年文献,介绍上转换发光纳米材料的发光机理、发光性能及调控、光学材料打印技术的研究进展。结果 稀土掺杂的上转换发光纳米材料表现出优异的发光性能,但随着粒径减小,纳米颗粒出现发光效率、量子产量低的问题。利用纳米颗粒表面钝化、表面等离子体耦合、与有机配体结合和外场调节等手段,可以使发光材料的发光效能显著增强。利用喷墨打印、丝网印刷、纳米压印光刻和气溶胶喷印等技术,可以使稀土掺杂的上转换发光纳米材料被打印成多样的防伪图案,在光学防伪、信息存储与标记等领域具有重大应用潜力,有望成为新型功能包装材料。结论 在光学材料合成技术、光学调控和打印技术的共同推动下,稀土掺杂上转换发光纳米材料因其特殊的光学特性,有望为功能化包装防伪技术作出贡献。 相似文献
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测量不确定度直接评定法和综合评定法的几个典型实例第一讲直接评定法及其实例 总被引:1,自引:0,他引:1
王承忠 《理化检验(物理分册)》2006,42(4):210-215
采用直接评定法评定了带肋钢筋拉伸性能、金属材料维氏硬度检测结果的测量不确定度,用综合评定法评定了金属材料夏比缺口冲击试验、洛氏硬度检测结果的不确定度。结果表明,综合评定法在这些典型实例中解决了金属材料理化检测结果测量不确定度评定的某些难点。 相似文献
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The work was to investigate the possibility of making polymer–inorganic nano-composite films with upconversion fluorescence properties using the double beam matrix-assisted pulsed laser evaporation (DB-MAPLE) method. The existing pulsed laser deposition vacuum chamber was modified to accommodate two laser beams of different wavelengths for simultaneous ablation of two separate targets: a polymer host and a rare earth containing rare earth ion enriched upconversion fluoride dopant. The polymer target was prepared in chlorobenzene and kept frozen during the ablation with circulating liquid nitrogen in accordance with the MAPLE procedure. It was ablated with 1064 nm beam from a pulsed Nd:YAG laser. The pellets made of the synthesized powders of inorganic phosphors of NaYF4:Yb3+, Er3+ and NaYF4:Yb3+, Ho3+were ablated with 532-nm beam from the same laser. The plumes from both targets were kept overlapping on the substrate during the deposition. X-ray diffraction analysis revealed that the most favorable for upconversion emission of the inorganic target materials was the hexagonal, beta phase of the NaYF4 matrix existing at a baking temperature between 400 and 600 °C. The fabricated nano-composite films were characterized using scanning electron microscopy (SEM), atomic force microscopy (AFM), transmission electron microscopy (TEM) and optical fluorescence spectroscopy. The polymer nano-composite films generally retained the crystalline structure and the upconversion fluorescence properties of the initial rare earth compounds due to better control of the deposition process of the materials with substantially different properties. The proposed method can be potentially used for making a wide variety of nano-composite films. 相似文献