SiC纳米颗粒的制备与发光特性研究

采用热化学气相沉积的方法首先合成了SiC纳米颗粒。接着,用扫描电子显微镜、透射电子显微镜、拉曼光谱、X射线电子能谱和X射线衍射谱等表征了材料的结构和组成。最后,利用光致发光谱和光致发光谱微区成像系统研究了材料的光学性质。实验结果表明,制备的纳米材料的尺寸约为70～90 nm;发光带由中心波长分别为530和542 nm的绿光发光峰组成,分析认为分别来自于SiC材料本身和表面缺陷;在相同的激发光强度下,材料最大发光强度相对于相同条件下合成的体材料提高5倍左右。制备的SiC纳米材料在绿光光电子器件领域有着潜在的应用价值。     

稀土激活发光材料的研究进展

稀土发光材料是一种很有发展前途的新型功能材料.介绍了稀土发光材料的性质和应用,详细阐述了高温固相、共沉淀、燃烧、气体反应、水热和微波等稀土发光材料的制备方法,探讨了稀土离子对发光材料的激活机理,并展望了该领域的发展前景.作者利用燃烧法制备出以SrAl2O4为基质,稀土元素铈和铽为激活剂的光致黄色荧光发光材料,显示了其优越的发光性能.     

稀土离子掺杂及制备方法对钛酸盐发光材料性能影响的研究及展望

钛酸盐发光材料是一类新型的功能材料,物理化学性能稳定。由于钛酸盐具有较低声子能量和高振动频率,宜用作发光基质材料。综述了不同稀土离子掺杂对钛酸盐发光材料性能的影响,总结了钛酸盐发光材料的制备方法以及各种方法制备的产品形貌及性能等特点,并提出了今后可能的研究与应用发展方向。     

化学气相沉积法制备SiC纳米线的研究进展

SiC纳米线具有优良的物理、化学、电学和光学等性能,在光电器件、光催化降解、能量存储和结构陶瓷等方面得到广泛应用.其制备方法多种多样,其中化学气相沉积法(CVD)制备SiC纳米线因具有工艺简单、组成可控和重复性好等优点而备受关注.近年来,在化学气相沉积法制备SiC纳米线以及调控其显微结构方面取得了较多成果.采用Si粉、石墨粉和树脂粉等低成本原料以及流化床等先进设备,通过化学气相沉积法制备出线状、链珠状、竹节状、螺旋状以及核壳结构等不同尺度、形貌各异的SiC纳米线,并且有的SiC纳米线具有优良的发光性能、场发射性能和吸波性能等,为制备新型结构和形貌的SiC纳米线及开发新功能性的SiC纳米器件提供了重要参考.目前,未添加催化剂时,利用气相沉积法制备的SiC纳米线虽然纯度较高,但存在产物形貌、尺度和结晶方向等可控性差,制备温度较高和产率相对较低的问题.而添加催化剂、熔盐以及氧化物辅助可明显降低SiC纳米线的制备温度,提高反应速率以及产率,但易在SiC纳米线中引入杂质.将来应在提高SiC纳米线的纯度、去除杂质方面开展深入研究;还应注重低成本、规模化制备SiC纳米线的研究,采用相应措施调控SiC纳米线的显微结构,以拓宽SiC纳米线的应用领域.本文综述了目前国内外采用化学气相沉积制备SiC纳米线的方法,分析总结了无催化剂、催化剂、熔盐以及氧化物辅助等各种制备方法的优缺点,并对未来的研究进行展望,期望为SiC纳米线的低成本、规模化制备和应用提供理论依据.     

稀土发光材料的研究进展

稀土发光材料是一类很有发展前途的新型功能材料.综述了国内外稀土发光材料的研究进展,总结了稀土发光材料的种类、发光特性、应用、制备方法和发光机理等,同时分析了稀土发光材料在发展过程中亟待深入研究的问题,最后展望了其发展前景.     

长余辉发光材料研究进展

主要综述了长余辉发光材料的制备方法的进展及其发光机理,并根据最近研究的热点综述主要激活剂组分在发光材料中的作用和助熔剂组分B2O3对发光材料晶相的稳定和发光性质的作用.     

发光纤维的研究进展

近年来由于不可再生资源的日益枯竭,以及环境危机等问题,发光材料的研究和利用受到人们的广泛关注。发光纤维作为发光材料的一种,更是有其独特的性能,具有无毒、无害、色泽光鲜亮丽、材质柔和、抗衰老性优良、可持续发光等诸多优点。发光纤维分为荧光纤维和夜光纤维,夜光纤维又分为自发光型和蓄光型。发光纤维实现了自动吸光-蓄光-发光这一循环功能,发光纤维的开发利用是应对资源匮乏、实现化纤工业可持续发展的需要,同时也是实现节能减排、发展低碳经济的需要。发光纤维材料的应用领域包括但不限于发光印花织物、发光纺织品的应用、玩具和刺绣艺术品、功能服装、防伪等。笔者对发光纤维材料方面的代表性成果进行梳理与总结,主要包括发光材料的分类及其应用、发光纤维简介及制备方法、发光纤维特性及其应用,并且对该领域内存在的问题及未来发展方向作了展望。     

稀土发光材料的合成、发光机理及今后展望

稀土发光材料是发光领域的一个研究热点。材料的合成方法与其发光性能有着紧密的联系,综述了5种不同的制备方法,如沉淀法、水热法、燃烧法、溶胶-凝胶法和高温固相法等,并简述了各自的实验原理及其合成过程中的优缺点。简单介绍了稀土发光材料的发光原理,即稀土元素在晶格中充当发光中心。最后对稀土发光材料的研究和应用进行了展望。     

照明装饰用新型塑料光纤

简述了塑料光纤用于照明装饰的特点 ,介绍了端面发光塑料光纤和通体发光塑料光纤的结构原理、制备方法以及应用场合。塑料光纤在照明装饰行业应用前景广泛 ,将会形成一个新型的塑料光纤照明装饰产业     

用于包装防伪的稀土上转换发光材料

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。     

Luminescence properties of zirconia nanocrystals prepared by solar physical vapor deposition

Zirconia nanocrystals have attracted considerable interest as biolabels, which can be used as probes for medical imaging and biosensor applications. However, zirconia particle agglomeration forms a major limitation to its use for biolabeling. In this backdrop, for the first time, well-separated zirconia nanocrystals were obtained in a Heliotron reactor (PROMES CNRS, France) via the solar physical vapor deposition (SPVD) method. As the raw material target for solar evaporation, zirconia nanopowders obtained via the sol–gel process were used. The luminescence and upconversion luminescence properties of the Sol Gel nanopowders were compared with those of the SPVD nanocrystals. Erbium was chosen as the luminescence center with ytterbium as the sensitizer, and along with these two dopants, niobium was also used. Niobium acts as a charge compensator to compensate for depletion in the charge due to the introduction of trivalent erbium and ytterbium at tetravalent zirconium sites. Consequently, the oxygen-vacancy concentration is reduced, and this results in a significant increase in the upconversion luminescence.The SPVD-prepared samples showed less agglomeration and a fine crystal structure as well as high luminescence, and thus, such samples can be of great interest for biolabeling applications.     

烧成条件对长余辉蓄光玻璃光学性能的影响

以ＳｒＡｌ_２Ｏ_４：Ｅｕ,Ｄｙ长余辉发光粉体和低熔点硼硅酸盐玻璃为原料,在一定条件下合成了长余辉蓄光玻璃．研究结果表明,烧成温度和保温时间对该玻璃的发光效果影响较大．温度越高,保温时间越长,由于空气的氧化作用,蓄光玻璃的发光效果越差,本试验控制烧成温度在７５０～８００℃间,保温时间在 １０ｍｉｎ以内,能合成性能较好的蓄光玻璃．余辉衰减曲线表明蓄光玻璃的发光性能较之原始发光粉体有所下降．ＳＥＭ分析表明,低温合成的蓄光玻璃中,所含能继续保持发光性质的粉体料,明显比高温合成样要多．     

上转换荧光材料在生物芯片技术中的应用

介绍了上转换荧光材料的特点、应用和发展状况,特别是上转换荧光材料在生物芯片技术中的应用前景.分析了在生物芯片技术中理想荧光探针应具有的特性,并总结了上转换荧光探针比目前正在使用的荧光探针的优点.提出了把上转换荧光材料应用于生物芯片技术中的实施方案和需要解决的问题.     

808‐nm‐Light‐Excited Lanthanide‐Doped Nanoparticles: Rational Design,Luminescence Control and Theranostic Applications

808 nm‐light‐excited lanthanide (Ln³⁺)‐doped nanoparticles (LnNPs) hold great promise for a wide range of applications, including bioimaging diagnosis and anticancer therapy. This is due to their unique properties, including their minimized overheating effect, improved penetration depth, relatively high quantum yields, and other common features of LnNPs. In this review, the progress of 808 nm‐excited LnNPs is reported, including their i) luminescence mechanism, ii) luminescence enhancement, iii) color tuning, iv) diagnostic and v) therapeutic applications. Finally, the future outlook and challenges of 808 nm‐excited LnNPs are presented.     

Near-infrared light activated persistent luminescence nanoparticles via upconversion

Persistent luminescence nanoparticles (PLNPs) and upconversion nanoparticles (UCNPs) are two special optical imaging nanoprobes.In this study,efficient upconverted persistent luminescence (UCPL) is realized by combining their unique features into polymethyl methacrylate,forming a film composed of both PLNPs and UCNPs.The red persistent luminescence (～640 nm) of the PLNPs (CaS∶Eu,Tm,Ce) can be activated by upconverted green emission of UCNPs (β-NaYF4∶Yb,Er@NaYF4) excited by near-infrared light (NIR).Using this strategy,both the unique optical properties of PLNPs and UCNPs can be optimally synergized,thus generating efficient upconversion,photoluminescence,and UCPL simultaneously.The UCPL system has potential applications in in vivo bioimaging by simply monitoring the biocompatible low power density of NIR-light-excited persistent luminescence.Due to its simplicity,we anticipate that this method for the preparation of UCPL composite can be easily adjusted using other available upconversion and persistent phosphor pairs for a number of biophotonic and photonic applications.     

Enhanced visible luminescence and modification in morphological properties of cadmium oxide nanoparticles induced by annealing

Cadmium oxide nanoparticles synthesised by a simple sol–gel synthesis method showed luminescence properties in the visible region of the electromagnetic spectrum. Both green and blue emissions were observed in photoluminescence spectra. We have investigated luminescence properties by changing the synthesis conditions. An enhanced luminescence of CdO nanoparticles was realised when these particles were annealed at different temperatures. Cadmium interstitial vacancies and oxygen vacancies played an important role in luminescence properties. X-ray diffraction confirmed annealing-induced changes in morphological properties. A good correlation between all the experimental results was obtained. Optical properties were investigated by diffuse reflectance spectra and photoluminescence spectra. Structural properties were investigated by high-resolution transmission electron microscopy.     

提高掺Er硅发光效率的途径与前景

阐述了掺Ｅｒ硅发光的研究意义和现状,总结了掺Ｅｒ硅的材料性能、发光机理、提高发光效率的途径、制备方法,以及掺Ｅｒ硅ＬＥＤｓ器件的行为和未来展望。     

多孔硅基体系发光特性研究进展

综述了多孔硅基复合体系发光特性的研究进展，阐述了多孔硅基体系及其发光特性，详细介绍了影响多孔硅基体系发光特性的因素和制备多孔硅基体系的方法，并讨论了多孔硅基体系的发光机理。最后综述了目前有待于进一步深入研究的问题及发展趋势。     

Luminescence properties of Ti-doped gem-grade zirconia powders

A detailed investigation on luminescence properties of gem-grade zirconia (NFC) as a function of Ti doping is presented. The effect of various parameters such as Ti concentration, environment of heat treatment and temperature was studied in detail and the optimum conditions for producing zirconia with luminescence properties comparable to standard material determined.     

Luminescence properties of spark-processed SiC

The photoluminescence (PL) properties of spark-processed SiC (sp-SiC) have been studied at various temperatures. Furthermore, scanning electron micrographs (SEM), X-ray diffraction (XRD) measurements, Fourier transform infrared (FTIR) spectroscopy, X-ray photoelectron spectroscopy (XPS), and Raman spectroscopy have been applied. The luminescence properties of sp-SiC are quite different from unspark-treated reference 6 H SiC. Specifically, the PL intensities of sp-SiC are at least two orders of magnitude larger than the reference SiC. Furthermore, the room temperature PL spectrum of sp-SiC exhibits two luminescence bands peaking at 3.18 eV, which are considerably blue shifted from SiC band gap of 2.9 and 2.43 eV. However, these two luminescence bands show an unusual red-shift of PL peak energies with decreasing temperature. Raman spectroscopy studies of sp-SiC display the emergence of a crystalline Si vibrational mode, whereas vibrational modes associated with 6H SiC are completely annihilated. XRD analysis exhibits the formation of polycrystalline Si after spark processing. Vibrational modes obtained from FTIR for sp-SiC are mainly composed of Si–O modes with some OH vibration. The results of low temperature PL studies, FTIR, XRD, XPS and Raman spectroscopy demonstrate that the luminescence properties of sp-SiC are similar to spark-processed Si.