基于局域表面等离子体增强的NaYF4：Yb/Er荧光上转换及其应用

阐述了局域表面等离子体共振增强荧光上转换的相关机制,并以此为基础总结了三种调节机制和四种上转换/金属复合材料结构。具有明显增强效果的上转换/金属结构复合材料大致分为四种:掺入Au和Ag纳米颗粒的稀土掺杂基质;core/shell结构;稀土掺杂的NaYF₄靠近金属颗粒或金属纳米线所形成的gap结构;周期性金属阵列结构。最后介绍了它们在生物医学和光电子器件领域的应用进展。     

稀土发光材料的发光机理及其应用

稀土是我国的重要战略资源,稀土发光材料在一些方面已得到普遍应用并在新能源和生物医学等方面具有重要的应用前景。该文给出了稀土离子发光材料的基本原理,介绍了含稀土离子发光材料在节能灯、白光半导体发光二极管显示(LED)用荧光粉、等离子显示(PDP)用荧光粉等领域的应用,对在上转换发光、生物荧光标记和下转换提升太阳能效率等方面的应用前景进行了总结和展望。     

上转换发光的有效增强机制--上转换敏化方法

频率上转换研究发现于四五十年代,在近十年稀土离子的频率上转换有了突飞猛进的发展,由其发展出来的应用技术也很有价值,但仍然面临着进一步提高上转换效率的任务,这也是上转换研究的核心问题．由于Ｙｂ３＋离子能级结构的特殊性,它的引入既可以通过能量传递导致共掺稀土离子上转换发光的较大增强,又可能不引 起较明显的荧光淬灭．因而研究Ｙｂ作为敏化中心的上转换敏化研究是有重要意义的,而把提高上转换效率与提高材料的物化性能结合起来更是上转换研究和应用的当务之急． 对于稀土激活中心（如 Ｅｒ３＋、 Ｔｍ３＋　、 Ｈｏ３＋…     

光谱选择性激光隐身材料研究现状

综述了稀土上转换、光子晶体和有机体系光谱选择性激光隐身材料的光谱选择吸收机理,稀土上转换材料通过上转换原理、光子晶体材料通过膜系材料结构设计、有机体系材料通过特定官能团振动均可实现特定波段光谱能量的选择性吸收。分析了三种光谱选择吸收材料应用于激光隐身的可行性和激光隐身的实现方式,综述了材料的研究现状。指出,光谱选择性激...     

稀土上转换发光微纳材料的光物理研究

稀土类发光材料由于其丰富的光学特性而具有重要的研究与应用价值。其中,稀土上转换发光材料在近年来尤为受人瞩目,与之相关的研究成果遍布物理、化学、生物、材料和多个交叉领域。有别于大多数发光材料的共性,上转换材料的激发-发射谱峰波长呈现为反斯托克斯位移,因此能够在短波长谱带范围绕过背景噪声且传输发光信息。作为对这一光物理机制的理解运用,人们通过化学方法合成了纳米尺度的稀土上转换发光材料,并且在生物样品荧光显微成像中成功证实了上转换发光标记物的高信噪比检测。以上转换发光微纳材料的光物理性质研究为主题,介绍和梳理了稀土上转换纳米材料在偏振光谱解析、单纳米颗粒超分辨发光成像、微型激光器构筑方面的研究进展。     

ZnO透明电极

冈本硝子公司开发了紫外光转换成可见光的荧光玻璃。在玻璃中掺入纳米半导体材料和稀土材料，通过改变半导体材料和稀土材料的组分，可得到红、绿、蓝、黄色发光。由于基质材料是玻璃，因此耐高温、寿命长。此种玻璃板可作为白色光源，也可用于紫外光传感器。     

氟化物玻璃在两束激光作用下的上转化三维立体显示

研究了两束激光作用下的上转换三维(3D)立体显示,所用材料为ZBLAN:Pr,Yb氟化物玻璃。所用的两束激光是波长分别为960 nm(半导体激光器)和820 nm(Ti宝石激光器)。对Pr3+离子双频上转换发光进行了研究,分析了上转换发光强度与抽运光强度和离子掺杂浓度的关系,从而得出了实现较清晰双频上转换3D立体图像的实验条件。ZBLAN玻璃为双频上转换3D立体显示的基质材料,主要由于其有非常好的声子光谱声子频率小于580 cm-1;当激光强度很小时,上转换荧光强度将随着两抽运激光强度的增加而线性增加;ZBLAN玻璃中Pr3+离子和Yb3+离子的最佳掺杂摩尔分数为0.5%和1.5%。     

Yb3+/Er3+共掺ZnF2粉末上转换发光特性研究

为了研究ZnF₂作为基质材料、稀土离子Yb3+和Er3+共掺摩尔分数不同时的发光性能,采用高温固相法,在820℃时制备稀土掺杂ZnF₂样品,并对各个样品进行上转换发射光谱测试。将激发功率与上转换发射功率进行曲线拟合,确定Yb3+和Er3+光子吸收过程。结果表明,在980nm半导体激光器激发下,样品在可见光区域内存在533nm,555nm和655nm 3个上转换发射峰,发射的红光强度大于绿光强度,吸收光子数目依次为1.73,1.75,1.88,确定3个发射峰均对应于双光子吸收。此研究说明稀土离子掺杂ZnF₂材料将在上转换红色荧光粉领域有重要的应用前景。     

NaYF_4:Er/Yb上转换材料的优化制备及其特性研究

针对第3代太阳电池用上转换材料,采用改良的水热技术优化制备了掺杂稀土离子的纳米氟化钇钠(NaYF4)上转换荧光材料。主要关注了有机溶剂和螯合剂对制备上转换材料性能的影响。测试结果表明:有机溶剂乙醇可以有效地抑制YF3等杂峰;螯和剂乙二胺四乙酸二钠(EDTA)可以分散颗粒达到增大颗粒表面积的作用;制备获得了具有六角晶向结构的Yb3+/Er3+共掺上转换材料,其上转换发射出能够被太阳电池有效吸收利用的红光(653 nm)和绿光(5205、40 nm)。     

掺Yb~(3+)/Er~(3+)石英光纤中频率上转换的实验研究

首次报道了实验研究连续1064nm Nd:YAG激光器泵浦的掺稀土离子Yb~(3+)/Er~(3+)石英光纤中频率上转换过程。测量了掺Yb~(3+)/Er~(3+)石英光纤产生的频率上转换可见荧光谱,并用能量转移、受激态吸收和双光子吸收过程解释了467,546和667nm三条频率上转换荧光谱线的产生机理。     

偏振发光的钙钛矿纳米线薄膜

偏振发光薄膜在液晶显示中有潜在的应用,可有效降低能耗。制备偏振发光薄膜的关键在于对发光材料进行有序的取向。以各向异性的CsPbBr₃纳米线为发光材料,使用偏心旋涂法对其进行取向并制备偏振发光薄膜。采用荧光光谱仪测试薄膜的偏振度,使用扫描电镜观察纳米线的取向形貌。通过改变偏心旋涂的基底、纳米线分散液的浓度和溶剂组分来优化纳米线薄膜的取向,获得了良好的荧光偏振度。     

氟硼酸盐玻璃的上转换发光

制备了Er^3＋离子掺杂的Yb^3＋离子氟硼酸盐玻璃,利用R-500型分光光度计,测量了样品在980mn和488mn激光激发下的发光特性,并就其红外上转换机制展开了讨论。     

Er3+/Yb3+共掺氟氧微晶玻璃的光谱性质及Judd-Ofelt理论分析

制备了新的Er3+/Yb3+共掺氟氧硅酸盐微晶玻璃,测试了荧光光谱、吸收光谱。研究了氟氧化物微晶玻璃中Er3+离子的上转换发光特性,采用Judd-Ofelt理论对样品光谱进行了分析,拟合得到了强度参数,Ω2=4.4756,Ω4=1.0059,Ω6=1.2098。计算了样品的辐射寿命、跃迁几率、荧光分支比等光谱参数。结果表明,样品通过热处理形成了氟化物微晶,降低了声子能量,提高了上转换效率。绿光、红光上转换荧光强度比玻璃样品增强约2到3倍。Judd-Ofelt理论分析表明Er3+/Yb3+共掺氟氧微晶玻璃具有较高的上转换效率,是制作微型激光器和三维立体显示的优良材料之一。     

稀土元素上转换材料在钙钛矿太阳能电池中应用的研究进展

无机有机杂化钙钛矿太阳能电池被认为是最有发展前景的第三代光伏技术之一,经过短短几年时间的研究,钙钛矿太阳能电池现今的最高效率已经突破22%.随着钙钛矿太阳能电池的效率越来越接近理论效率,为了进一步提升电池效率,研究人员将目光投向了钙钛矿材料不能有效吸收的近红外波段.在本文中,我们回顾了近两年来将上转换材料与钙钛矿太阳能电池相结合的研究,将它们分成较为传统的方法和新型方法.传统的方法即是使用较为单一的NYF纳米颗粒对钙钛矿太阳能电池进行掺杂,利用稀土离子的上转换效应,吸收近红外光,扩宽钙钛矿的吸收范围,从而提升太阳能电池的性能;而新型的方法即是在传统的单一使用稀土离子的基础上,添加其他离子或者引入重掺杂半导体材料来进一步提升太阳能电池性能的方法,从实验结果看,这两种方法都取得了较好的结果.     

Semiconductor infrared up-conversion devices

Various infrared up-conversion techniques have been developed, driven by applications including lasing, laser cooling, and infrared imaging. In this review article, we first present a brief overview of existing up-conversion techniques and then discuss in detail one particular approach. Among all types of up-conversion techniques, an integrated semiconductor photodetector-light-emitting diode (PD-LED) up-conversion device is the most promising one for infrared imaging applications. By now, PD-LED devices relying on various mechanisms, using different materials and structures, aiming at different wavelength regions, have been developed, and pixelless infrared imaging prototype devices have been demonstrated. We report the progress of semiconductor PD-LED up-conversion devices, and point out directions for future improvement.     

Spectral properties and energy transfer in Er3+/Yb3+ co-doped LiYF4 crystal

Laser crystals of LiYF4 (LYF) singly doped with Er3+ in 2.0% and co-doped with Er3+/Yb3+ in about 2.0%/1.0% molar fraction in the raw composition are grown by a vertical Bridgman method. X-ray diffraction (XRD), absorption spectra, fluorescence spectra and decay curves are measured to investigate the structural and luminescent properties of the crystals. Compared with the Er3+ singly doped sample, obviously enhanced emission at 1.5 μm wavelength and green and red up-conversion emissions from Er3+/Yb3+ co-doped crystal are observed under the excitation of 980 nm laser diode. Meanwhile, the emission at 2.7 μm wavelength from Er3+ singly doped crystal is reduced. The fluorescence decay time ranging from 18.60 ms for Er3+ singly doped crystal to 23.01 ms for Er3+/Yb3+ co-doped crystal depends on the ionic concentration. The luminescent mechanisms for the Er3+/Yb3+ co-doped crystals are analyzed, and the possible energy transfer processes from Yb3+ to Er3+ are proposed.     

New Ternary Europium Aluminate Luminescent Nanoribbons for Advanced Photonics

Developing novel one‐dimensional (1D) luminescent nanostructures (e.g., nanowires and nanoribbons) is highly desired for enabling progress in nanophotonics and other emerging optical technologies. Previous studies on 1D luminescent nanostructures were mostly focused on elemental and binary semiconductor materials, the light emission of which originates from the radiative recombination of electrons and holes via either intrinsic states or extrinsic defect states. Herein, three kinds of ternary europium aluminate nanoribbons are reported that have localized Eu²⁺ luminescent centers and exhibit new compositions, new crystal lattice structures, and new luminescence properties and mechanisms. These three europium aluminate nanoribbons are: blue luminescent EuAl₆O₁₀ with a new composition and a new tetragonal lattice structure, green luminescent EuAl₂O₄ with a monoclinic lattice structure, and orange luminescent EuAl₂O₄ with a new hexagonal lattice structure and extremely large band width and Stokes shift of emission. These materials have promising applications as nanometer‐scale light generators and waveguides in nanophotonics and as light converting phosphors in warm white light‐emitting diodes.     

Discovering and Dissecting Mechanically Excited Luminescence of Mn2+ Activators via Matrix Microstructure Evolution

Mechanoluminescent (ML) materials featuring renewable mechanical-to-optical conversion have shown promising prospects in stress sensing, lighting, and display. However, the advancement in ML applications is being restrained by the obstacles in developing efficient ML materials and understanding the underlying ML mechanisms. Herein, a matrix evolution strategy to modulate the local microstructure and electronic environment around the luminescent activators is proposed, which not only supports the batch development of new ML materials but also provides a well-connected platform for systematically revealing the mechanism of achieving efficient ML performance. The feasibility of the strategy is proved by constructing and evaluating a series of ML materials with matrix-dependent luminescent properties in experimental-theoretical collaboration. It is demonstrated that the construction of piezoluminescence is available in both non-centrosymmetric and centrosymmetric matrices without being restricted by lattice symmetry. The inter-electronic-levels and shallow electron traps formed by activator doping enhance the electron recombination efficiency through tunneling and conduction band transfer pathways. The results are expected to accelerate the exploitation of ML material systems and to deepen the comprehensive apprehending of ML mechanisms, thereby guiding the rational design and widespread use of efficient ML materials.