YXO4(X=Nb,V)的结构与基质发光

采用高温固相法制备了一系列YNb_1-xO₄∶xV样品, 通过连续改变Nb和V的比例获得了具有不同结构的材料. 研究发现, V$O^{3-}_{4}$与Nb$O^{3-}_{4}$基团的发光分别位于约420和400 nm处, 但是YNbO₄中掺杂少量的V ⁵⁺和YVO₄中掺杂少量的Nb ⁵⁺对发光的影响明显不同. 通过连续改变V和Nb的比例, 其发光性质并不能连续从一种发光变为另一种发光, 而是在某一组成时达到最低. 对所制备材料的结构、 组成及发光变化进行了研究, 结果表明存在2种发光猝灭机理.     

掺杂B^3＋在SrA12O4：Eu，Dy中的作用及其机制研究

研究了H38O3在碱土铝酸盐长余辉发光材料中的作用，发现H38O3不但影响固相反应速度，还对粉体晶相组成、粒径以及长余辉发光性能产生很大的影响。TG—DTA，XRD和SEM分析表明，H3803参与了固相反应，降低了成核温度与界面反应能垒，使晶粒生长反应速度加快，粉体粒径增大。激发与发射光谱、发射峰强度衰减以及热释光谱分析表明，H3BO3的掺人使发光中心离子浓度增加、陷阱深度和密度加大，从而使发光亮度增加，余辉寿命延长。     

高效长余辉发光薄膜及粉体的溶胶—凝胶工艺研究

研究了溶胶－凝胶工艺制备SrAl2O4:Eu^2 ,Dy^3 高效长余辉发光薄膜及粉体的工艺条件,以无机盐为原料,成功制备了均一、稳定、透明的SrAl2O4溶胶,并在较低温度下制备了均匀、无裂纹的发光薄膜和颗粒均匀的针状纳米发光粉体。通过热失重和X射线衍射结果分析了样品的结晶过程和晶相组成,并通过扫描电镜、透射电镜和荧光光谱的分析对薄膜和粉体的微结构、表面形态及发光性能进行了表征。结果表明,在本文的工艺条件下,制备的薄膜和粉体的发光特性与传统的高温固相烧结法相似,但烧结温度可降低300℃左右。     

锶铝比对稀土掺杂铝酸锶物相及发光性能的影响

用拟薄水铝石溶胶凝胶法成功制备了SrAl2O4：Eu^2 ，Dy^3 长余辉发光材料，样品无需球磨。XRD结果表明：当锶铝摩尔比Sr／Al＞0．3时，发光基质主相为SrAl2O4，杂质相为Sr4Al2O7，Sr／Al比值继续降低至0．25，发光相则以Sr4Al14O25为主，此时杂质相中含有Sr4Al2O7和Dy4Al2O9。Sr4Al2O7相对SrAl2O4：Eu^3 ，Dy^3 的发光性能影响很大，而对Sr4Al14O25：Eu^2 ，Dy^3 的发光性能影响不大。Dy4Al2O9对SrAl2O4和Sr4Al14O25发光主相的发光性能影响都不大。光谱检测结果表明SrAl2O4：Eu^2 ，Dy^3 发光光谱是中心位于520nm的带状谱。余辉检测结果表明发光主相为SrAl2O4和Sr4Al14O25时，光衰曲线符合I=ct^-n规律，n值分别为n=1．081和n=1．079。     

掺杂B3+在SrAl2O4∶Eu,Dy中的作用及其机制研究

研究了H3BO3在碱土铝酸盐长余辉发光材料中的作用, 发现H3BO3不但影响固相反应速度, 还对粉体晶相组成、粒径以及长余辉发光性能产生很大的影响. TG-DTA, XRD和SEM分析表明, H3BO3参与了固相反应, 降低了成核温度与界面反应能垒, 使晶粒生长反应速度加快, 粉体粒径增大. 激发与发射光谱、发射峰强度衰减以及热释光谱分析表明, H3BO3的掺入使发光中心离子浓度增加、陷阱深度和密度加大, 从而使发光亮度增加, 余辉寿命延长.     

锐钛矿/金红石TiO_2相结界面电荷分离的时间分辨发光光谱研究（英文）

"结"的构筑,被证实是提高电荷分离效率的重要策略,在太阳电池、光催化等领域有广泛应用.跟踪研究异质结、异相结处的电荷转移动力学,可深入认识结的作用,进一步指导新材料、新结构的设计合成.锐钛矿/金红石Ti O_2异相结,可大大提高Ti O_2光催化重整生物质制氢的产氢性能.锐钛矿/金红石异相结处的电荷分离、复合等动力学行为还亟需进一步深入研究,我们使用时间分辨发光光谱技术,重点研究了锐钛矿和金红石界面处的电荷转移过程及其对电荷复合过程的影响机制.我们制备了一系列具有不同晶相组成的Ti O_2催化剂,使用XRD和表面灵敏的紫外拉曼光谱表征确定了样品的表面和体相组成,研究其光致发光性质并与其晶相组成相关联.发现,Ti O_2的发光行为与其晶相结构直接相关,特别是与其表面晶相结构存在密切关系.其中,500 nm的可见发光带与锐钛矿晶相相关,而835 nm的近红外发光带与金红石晶相相关.分析可见发光带强度随Ti O_2晶相组成的变化,发现Ti O_2粒子中存在少量金红石成分时,可见发光带强度不仅未猝灭,反而有一个明显的增强效应,同时,近红外发光峰的出现也存在一定的延后现象.这些结果表明锐钛矿/金红石异相结处存在金红石向锐钛矿的电荷转移过程.进一步,使用时间分辨发光光谱研究可见发光带和近红外发光带的衰减动力学,从而分析揭示锐钛矿/金红石相结对锐钛矿和金红石的载流子动力学的影响机制.对于可见发光带来说,锐钛矿/金红石异相结的存在使可见发光带的衰减速率在微秒时间尺度减慢,而在毫秒时间尺度反而衰减变快.在金红石为主要晶相的混相氧化钛中(如Ti O_2-800),还观测到了一个新的约0.43ms的快衰减成分,表明锐钛矿向金红石的载流子转移过程.对于近红外发光带来说,与可见发光带类似,在微秒时间尺度的衰减也明显变慢,寿命可增长一倍以上,而在毫秒时间尺度的衰减速率没有明显变化.特别是,在锐钛矿/金红石异相结存在条件下,除长于40ms的微秒衰减成分外,基本所有混相Ti O_2样品都显示出~2ms的快衰减成分,且此快衰减成分的比例受样品晶相组成、制备方法等影响,可达到22%左右.这一快衰减成分的出现,证明了锐钛矿/金红石异相结处存在金红石向锐钛矿的载流子转移过程.我们通过发光光谱技术研究了锐钛矿/金红石异相结在电荷分离复合过程中的作用.研究发现,锐钛矿/金红石相结存在条件下,可见和近红外发光带都出现了一个新的快衰减成分,证明相结处存在快速的电荷分离过程.由于相结促进电荷分离,在微秒时间尺度抑制了电荷复合,从而使发光衰减明显变慢.而在毫秒时间尺度,电荷复合速率并没有抑制效果.因此,我们提出锐钛矿/金红石相结对光催化活性的促进作用,主要是因为微秒时间尺度促进电荷的有效分离,从而使微秒时间尺度存在更大量的光生电荷参与光催化过程.     

铜(II)-铬(VI)复合均匀胶体粒子的制备

报导在尿素存在下通过均相沉淀法由硝酸铜和重铬酸铵制备复合均匀胶体粒子的结果．研究了一些实验参数对其组成、形态和粒子大小的影响．确定了胶体粒子的制备条件．结果观测到，由硝酸铜和重铬酸铵溶液形成了球形的多刺的粒子，它的组成为水含铅酸铜．     

长余辉发光玻璃SrAl2O4∶Dy, Eu的制备与发光性能研究

在低熔点破璃中掺杂一定量的长余辉发光粉制备了性能优良的长余辉发光玻璃。在保证发光玻璃均匀透明的基础上，发光性能随发光粉掺杂量的增加而增强，尽量降低假烧温度和减少保温时间可以保持良好的发光性能，在还原气氛制备的发光玻璃性能优于在空气中制备的。煅烧工艺对发光玻璃的微观结构有显著的影响。     

溶胶-凝胶工艺制备发光薄膜研究进展

本文综述了通过深胶－凝胶工艺制备发光薄膜的基本过程、薄膜的表征方法、发光薄膜的当前发展及应用情况。依据组成特点,对溶胶－凝胶法制备的发光薄膜乾地了分类阐述,并预言了今后该法制备发光薄膜的发展趋势。     

稀土红色长余辉发光材料研究进展

综述了稀土元素掺杂红色长余辉发光材料的研究进展，总结了硫化物、钛酸盐、硫氧化物、硅酸盐、氧化物和磷酸盐等基质体系的红色长余辉发光，并指出硫氧化物和磷酸盐等基质是最具有发展前景的红色长余辉发光体系，讨论了Eu^2 在硫化物、Pr^3 在钛酸盐以及Eu^3 和Sm^3 等稀土离子在硫氧化物和硅酸盐等体系中的红色长余辉发光机制。介绍了传统的高温固相法以及溶胶．凝胶法、微波合成法等稀土红色长余辉材料的制备技术。提出了从基质材料、制备技术和稀土离子发光机制入手是稀土红色长余辉发光材料今后研究与开发的发展方向。     

The study of preparation and luminescence of polymethyl methacrylate/rare earth composite luminescent materials

The alkaline-earth–rare-earth–aluminate systems phosphors are the new types of phosphors, which process very bright, safer, and excellent photoluminescence. Because of hydrolysis, however, the capacity of luminescent materials will fall down and the use value of luminescent materials will also be lost. Water-resistant polymers, which can form a kind of water-resistant clad on the surface of luminescent material powder, will solve this problem and the significance of its application is important. In this study, the polymethyl methacrylate (PMMA)/rare earth composite luminescent materials were prepared through grafting emulsion polymerization of methyl methacrylate onto the surface of luminescent materials. To study the structure and properties of the PMMA/rare earth composite luminescent materials, Fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), and photoluminescent properties were measured. From the curves of FTIR and TGA, we can find that the organic parts are attached with the inorganic parts in the PMMA/rare earth composite luminescent materials. The results of luminescent decay curves show that the resistance to water of the PMMA/rare earth composite luminescent materials is much better than that of the unmodified luminescent materials because the organic parts had been grafted on the luminescent materials.     

Reversible Luminescent Switching in an Organic Cocrystal: Multi-Stimuli-Induced Crystal-to-Crystal Phase Transformation

A luminescent cocrystal system is reported to undergo crystal-to-crystal phase transformation from yellow-emitting polymorph I to green-emitting polymorph II, triggered by THF fuming or heating, and the green emission can recover to the initial yellow emission by grinding. The established spectroscopic and crystallographic analyses demonstrate that the phase transition occurred and benefits from the combined effect of similar molecular arrange sequence and unique alteration of intermolecular interactions from halogen/hydrogen bonds in I to π–π stacking in II. Furthermore, I and II exhibit red-shift emission under hydrostatic pressure. The emission of I and II shows a red-shift and recovers towards the initial emission upon acid–base fuming. This is a rare example of reversible luminescent switching of cocrystal based upon crystal-to-crystal phase transition, and provides an alternative strategy to develop multi-stimuli responsive materials.     

Reversible Luminescent Switching in an Organic Cocrystal: Multi‐Stimuli‐Induced Crystal‐to‐Crystal Phase Transformation

A luminescent cocrystal system is reported to undergo crystal‐to‐crystal phase transformation from yellow‐emitting polymorph I to green‐emitting polymorph II, triggered by THF fuming or heating, and the green emission can recover to the initial yellow emission by grinding. The established spectroscopic and crystallographic analyses demonstrate that the phase transition occurred and benefits from the combined effect of similar molecular arrange sequence and unique alteration of intermolecular interactions from halogen/hydrogen bonds in I to π–π stacking in II. Furthermore, I and II exhibit red‐shift emission under hydrostatic pressure. The emission of I and II shows a red‐shift and recovers towards the initial emission upon acid–base fuming. This is a rare example of reversible luminescent switching of cocrystal based upon crystal‐to‐crystal phase transition, and provides an alternative strategy to develop multi‐stimuli responsive materials.     

New Strategy for Optimizing the Properties of Copper Halide Organic-Inorganic Hybrid Lighting-emitting Materials

Copper(I) halide organic-inorganic hybrid luminescent materials have many advantages, such as diverse structure, facile synthesis, high luminescent efficiency, tunable optical performance, etc., and show a broad application prospect in energy-saving lighting, display and other fields. However, compared with commercial rare-earth-metal-based phosphors, the reported hybrids generally suffer from poor stability and low luminescent efficiency, which are the bottleneck problem of their practical application. With the aim of developing high-performance organic-inorganic hybrid luminescent materials, a new synthesis strategy has been reported. This strategy can systematically design and synthesis copper(I) halide ionic hybrid structures by combining the covalent bonding and ionic bonding between inorganic and organic components into one structure, and use their synergistic effect to optimizing their properties. This design method is expected to develop high-performance organic-inorganic hybrid luminescent materials, promote the in-depth understanding of this field, and provide new ideas for the optimization of other types of hybrid materials.     

纳米发光材料研究的若干进展

本文综述纳米发光材料的研究进展情况,着重总结了（稀土）掺杂型纳米发光材料的制备方法和表征手段,同时介绍了这些纳米发光材料的性质和应用,并对其未来发展趋势进行了展望。     

Solid-state luminescence of Au(I) complexes with external stimuli-responsive properties

In the last decade, the field of stimuli-responsive luminescent materials have been intensely emerged because of the high potential application to functional sensors or photoelectronic devices. In particular, luminescent molecular crystals constructed from Au(I) complexes have produced a wide range of examples of luminescent alterations when some external stimulations, such as heat, mechanical stress, vapor (or solvents), were applied to the solid samples. In this review, we describe the recent progress through a summary of the reported Au(I) complexes based on their utilized stimuli-responsive mechanisms, which are categorized in crystal phase transitions (“crystal-to-amorphous”, “crystal-to-crystal” and “single-crystal-to-single-crystal” transitions) and molecular rotation in crystalline media, respectively.     

Mechanochromic Luminescence of Copper Iodide Clusters

Luminescent mechanochromic materials are particularly appealing for the development of stimuli‐responsive materials. Establishing the mechanism responsible for the mechanochromism is always an issue owing to the difficulty in characterizing the ground phase. Herein, the study of real crystalline polymorphs of a mechanochromic and thermochromic luminescent copper iodide cluster permits us to clearly establish the mechanism involved. The local disruption of the crystal packing induces changes in the cluster geometry and in particular the modification of the cuprophilic interactions, which consequently modify the emissive states. This study constitutes a step further toward the understanding of the mechanism involved in the mechanochromic luminescent properties of multimetallic coordination complexes.     

无机纳米稀土发光材料的制备方法*

无机纳米稀土发光材料作为一种重要的发光材料,由于具有独特的光、电和化学性质,使其在高性能磁体、发光器件、显示、生物标记、光学成像和光学治疗等方面得到了广泛的应用。稀土发光材料的这些性质与材料的尺寸和形状密切相关,近年来研究者已经利用多种合成方法制备了不同形状的纳米稀土发光材料,包括纳米线、纳米棒、纳米管、纳米纤维和纳米片等。本文综述了无机纳米稀土发光材料的几种常用的制备方法,包括水热/溶剂热法、有机/无机前驱体热分解法和超声辅助合成法等,评述了这些方法的优缺点,并结合课题组在无机纳米稀土发光材料制备方面的工作,对无机纳米稀土发光材料制备方法的发展进行了展望。     

近红外稀土荧光在功能材料领域的研究进展

稀土近红外荧光材料具有特征发射峰尖锐、光稳定性好和毒性低等特点。近年来,稀土近红外荧光材料在光纤通讯、激光系统、生物分析传感器及生物成像等方面的应用价值日渐突显,引起了研究者们的极大关注。特别是稀土近红外荧光材料已发展成一种新兴的荧光标记材料,并有希望替代有机染料和量子点应用于生物分析和医学成像。基于稀土近红外发光的荧光探针具有低自荧光背景、宽斯托克斯位移、强抑制光漂白、深层穿透组织和短暂分辨的优势,有潜力成为高灵敏度、高选择性的检测手段。利用稀土离子制备的各种荧光材料,如上转换纳米晶、介孔材料、脂基胶体、离子液体、离子胶体、金属有机框架等,由于荧光敏化机理不同,其近红外荧光性能也各有千秋。然而,稀土近红外荧光的真正挑战仍是提高近红外发光的量子效率。本文结合近红外荧光领域的最新进展,综述了不同的稀土近红外荧光设计思路,介绍了各种近红外稀土荧光功能材料,阐述了稀土离子在近红外荧光功能材料中的优势,并展望了稀土近红外荧光材料的发展前景。     

Recent advances in organic pressure-responsive luminescent materials

Pressure is a powerful tool to regulate the molecule aggregation and intermolecular interactions. Organic luminescent materials under high pressure can produce rich phenomena,which have many potential applications.