新型橙红色荧光粉Ba3-xSrNb2O9:xSm3+光致发光研究

采用高温固相法制备了一类新型橙红荧光粉Ba_3-xSrNb₂O₉:xSm³⁺,通过XRD图谱鉴定了样品的纯相结构。根据激发发射光谱，紫外激发406 nm下，该荧光粉在596 nm处呈现出明亮的橙红光发射，Sm³⁺的猝灭浓度为0.04。结合变温光谱，分析得出在高温453 K下，其PL发射强度仍保持在室温下的76.5%,具有良好的热稳定性。此外，通过将样品与蓝色LED芯片简易封装，在激发电流160 mA下，Sm³⁺掺杂荧光粉在色坐标(0.331 4, 0.338 1)下发出明亮的白光，接近理想白光(x=0.33,y=0.33),显色指数高达93.3。结果表明，作为新型铌酸锶钡基质的荧光粉，在掺杂稀土Sm³⁺后，在紫外白光发光二极管(UV-WLEDs)中具有极高的应用可行性。     

Sm3+离子掺杂对BaGa2O4∶Cr3+近红外长余辉发光的增强研究

利用高温固相法制备了BaGa₂O₄∶Cr³⁺,Sm³⁺(BGO∶Cr,Sm)近红外长余辉发光(PersL)材料，考察了Sm³⁺掺杂浓度和煅烧温度对BGO∶Cr,Sm晶体结构和发光性能的影响，初步探讨了近红外余辉发光机理。结果表明：当长余辉发光材料组成为BGO∶Cr_0.06,Sm_0.004且煅烧温度为1100℃时，可以获得高纯度的BGO∶Cr,Sm长余辉发光材料，其发射波长为734 nm。Cr³⁺与Sm³⁺共掺杂为应用于生物成像的BGO提供了优化策略，同时为开发长余辉发光材料提供了良好范例。     

Y3MgAl3SiO12:Dy 3+,Eu 3+荧光粉的能量传递与暖白光实现

采用高温固相法合成了Dy ³⁺、Eu ³⁺共掺杂Y₃MgAl₃SiO₁₂石榴石型荧光粉。采用XRD、荧光光谱仪等仪器对样品的结构以及光谱特性进行表征,探究了Dy ³⁺/Eu ³⁺在Y₃MgAl₃SiO₁₂基质结构中的光谱特征以及离子间的能量传递机制。在367 nm近紫外光激发下,Y₃MgAl₃SiO₁₂:Dy ³⁺,Eu ³⁺的发射光谱包含Dy ³⁺的6F9/2到6H15/2和6H13/2的电子跃迁特征发射(487 nm蓝光和592 nm黄光)和Eu ³⁺的5D0 7F2 and 5D0 7F4特征发射峰(616 nm和710 nm红光)。在400~500 nm范围内Dy ³⁺发射谱与Eu ³⁺激发谱重叠,表明Dy ³⁺与Eu ³⁺之间存在着能量传递,能量传递的机理为电四极-电四极相互作用。该荧光粉通过调整Dy ³⁺和Eu ³⁺的掺杂浓度比封装近紫外LED芯片,可以实现单基质暖白光LED照明。     

新型白光LED荧光粉Y2O3:Ti 3+的光谱性能

采用共沉淀法,在不同的烧结气氛下制备了Y₂O₃:Ti ³⁺粉体,测量了它们的激发、发射光谱以及XRD光谱,观测了形貌。在紫外光激发下,微晶Y₂O₃:Ti ³⁺在439nm附近有较强的发射带,而纳米Y₂O₃:Ti ³⁺在400~500nm范围内出现了强的发射带。随纳米粉体的晶粒尺寸减小,它的发光明显增强,覆盖了整个可见光区。结果表明Y₂O₃:Ti ³⁺纳米粉体有望成为新一代白光LED或汞灯的光转换荧光粉。     

纳米粉体Y2O3:Ti 3+ , Eu3+的光谱性能

采用共沉淀法在氮氢气氛中制备出Y₂O ₃:Ti ³⁺, Eu ³⁺纳米粉体,测量了它的XRD、激发与发射光谱,观测了形貌。通过与Y₂O ₃:Ti ³⁺纳米粉体的光谱比较分析,发现Y₂O ₃中的Ti ³⁺至Eu³⁺存在能量传递,以致紫外至蓝光区域的光,均能使Eu³⁺经5D0→7F2等跃迁通道发射出610nm左右的荧光,于是增强了粉体在红橙光区发光的比重,因此可以调节粉体的发光性能。Y₂O ₃:Ti ³⁺纳米粉体的吸收带从紫外延伸到蓝光区,强荧光带覆盖了整个可见光区,这预示它有望成为新一代白光LED或汞灯的光转换荧光粉。     

Sm3+掺杂(Na0.2Bi0.2Ba0.2Sr0.2Ca0.2)TiO3高熵粉体的制备及其荧光性能研究

采用固相法制备了稀土Sm³⁺(0～0.10 mol)掺杂的(Na_0.2Bi_0.2Ba_0.2Sr_0.2Ca_0.2)TiO₃高熵荧光粉。研究发现,随着Sm³⁺掺杂量的增加,(Na_0.2Bi_0.2Ba_0.2Sr_0.2Ca_0.2)TiO₃高熵粉体逐渐出现了Sm₂Ti₂O₇杂相,其发光强度发生明显变化。当Sm³⁺掺杂量为0.04 mol时,(Na_0.2Bi_0.2Ba_0.2Sr_0.2Ca_0.2)TiO₃高熵粉体具有单一的钙钛矿结构,且各元素组分分布均匀,并表现出最佳的荧光性能。当...     

GSA和ESA双波长泵浦2.3 μm波段Tm:YAP激光器

Tm³⁺离子³F₄能级的粒子数捕获效应是影响2.3μm掺铥激光器高效运转的重要因素。报道了基态吸收（GSA,³H₆→³H₄）和激发态吸收（ESA,³F₄→³H₄）双波长泵浦2.3μm波段Tm∶YAP激光器。使用785 nm（GSA）和1470 nm（ESA）双波长泵浦方案能够精准减少³F₄能级的粒子数,有效增加³H₄能级粒子数布居。在双波长泵浦沿a轴切割的Tm∶YAP晶体中,使用透过率T=1.5%的输出镜,2274 nm和2383 nm双波长激光最大输出功率为2.28 W,相比于单波长泵浦方案提高了65.2%。使用T=2.8%输出镜,2383 nm激光的最大输出功率为942 mW,较单波长泵浦方案提高了84.3%。通过采用特殊镀膜的输出镜,进一步实现了2446 ...     

Ag NPs induced near-infrared emission enhancement of Er3+/Tm3+ codoped tellurite glass

Ag nanoparticles(NPs) were introduced into Er³⁺/Tm³⁺ codoped tellurite glasses prepared using melt-quenching and heat-treated techniques. The glass samples were characterized by the differential scanning calorimeter(DSC), X-ray diffraction(XRD), transmission electron microscopy(TEM) and photoluminescence to reveal the Ag NPs induced broadband near-infrared band emission enhancement of Er³⁺/Tm³⁺ ions. The studied glasses possessed good thermal stability with△T larger than 137 ℃. For glass sample heat-treated at 360 ℃ for 6 h, the nucleated Ag NPs in near-spherical shape with an average diameter about 6.5 nm dispersed in the glass matrix. Under the excitation of 808 nm laser diode(LD), the broadband near-infrared fluorescence emission extending from 1 350 nm to 1 620 nm, owing to the combined contributions from the ³H₄→³F₄ transition of Tm³⁺ at 1.47 μm band and the ⁴I_13/2→⁴I_15/2 transition of Er³⁺ at 1.53 μm band, improved significantly with the introduction of Ag NPs, which is mainly attributed to the increased local electric field. The present results indicate that Er³⁺/Tm³⁺/Ag NPs codoped tellurite glass with good thermal stability is a promising glass material for broadband fiber amplifiers of WDM transmission systems.     

白光LEDs用(Ba/Sr/Ca)2.9Ce(PO4)3:0.1Eu2+的发光特性

采用高温固相法制备了(Ba/Sr/Ca)_2.9Ce(PO₄)₃:0.1Eu²⁺系列荧光粉,研究了材料的发光特性。在400 nm光激发下,增大x值,Ba_2.9-xSr_xCe(PO₄)₃:0.1Eu²⁺的主发射峰由515 nm红移至540 nm,色坐标从(0.312,0.607)变到(0.376,0.580);随着y值的增大,Ba_2.9-yCa_yCe(PO₄)₃:0.1Eu²⁺的主发射峰由515 nm红移到553 nm,色坐标从(0.312,0.607)变到(0.427,0.535),随z值的增大,Sr_2.9-zCa_zCe(PO₄)₃:0.1Eu²⁺的主发射峰值由540 nm红移...     

Bi3+, Eu 3+, Tb3+ 掺杂Lu3TaO7的发光性能研究

采用固相反应法制备了Bi ³⁺ 、Eu³⁺ 、Tb³⁺ 掺杂的Lu₃TaO₇。测量了样品的X射线衍射谱、激发和发射光谱及荧光衰减曲线。三种离子掺杂的Lu₃TaO₇均呈现出强的荧光发射,其中Bi³⁺具有峰位在431 nm处的一强发射宽带,衰减寿命为16.8 μs,Eu ³⁺ 、Tb ³⁺ 则表现出稀土离子的特征锐发射峰,衰减寿命分别为1.26 ms和1.20 ms。因此,它们均是具有潜在应用前景的重闪烁体材料。     

中频溅射技术制备镱铒共掺Al2O3光波导

在硅单晶(100)衬底上用热氧化法氧化一层SiO₂做缓冲层,在高纯铝靶上镶嵌金属Yb,Er,然后用中频磁控溅射法制备了镱铒共掺杂氧化铝薄膜。讨论了靶电压及沉积速率随氧流量的变化的磁滞回线效应,分析得出了沉积氧化物薄膜的最佳氧流量。在室温下检测到了薄膜的位于1535nm的很强的光致发光光谱(PL),并在光学掩模下用BCl₃离子束对薄膜样品进行刻蚀,得到条形光波导。     

Red to blue upconversion luminescence in Tm doped ZrF4-ZnF2-AlF3-BaF2-YF3 optical glass

We report on the preparation and optical spectroscopy analysis of a new fluoride glass in the chemical composition of 20ZrF₄-30ZnF₂-25AlF₃-10BaF₂-15YF₃ with Tm³⁺ as the luminescent ions. Under an UV source, this material has displayed an intense blue emission colour. Upon excitation with a red wavelength at 688 nm (³H₆→³F₃), this glass has shown two upconverted blue emissions at 452 nm (¹D₂→³F₄) and 474 nm (¹G₄→³H₆), respectively. Possible mechanisms involved in such upconverted blue emissions are explained via ground state absorption and excited state absorption processes through an energy-level structure diagram of Tm³⁺(4f¹²). By the successful application of Judd-Ofelt calculations, the luminescence results have successfully been analysed. Besides obtaining a clear understanding of the optical characteristics of this glass, we have also measured its physical properties such as the refractive indices at three different wavelengths in order to evaluate its light dispersion performance, glass density and other related parameters as well.     

用于白光LED的红色荧光粉SrAl2Si2O8:Eu3+,Li+的制备和发光性能研究

采用高温固相法制备了Sr1－x Al₂Si₂O₈:Eu³⁺ x,Li⁺0.03系列红色荧光粉,研究了试样的晶体 结构和发光性质。合成的试样均为纯相的SrAl₂Si₂O₈晶体,单斜晶系,空间群为 C2/m(12); Eu³⁺和Li⁺进入基质晶体中,使得SrAl₂Si₂O₈晶胞参数a、b和c 略微减小,只引起了晶体结构轻 微的畸变。试样的激发光谱由位于220~580nm波长的一个宽激发带 和一组锐线峰构成,其中 395nm波长处Eu³⁺的⁷F₀→⁵L₆激发峰的强度最强。发射光谱位于550~750nm波长范围内呈现多 条锐 线发射,其中595nm和615nm波长处发射峰最 强,分别归属于Eu³⁺的⁵D₀→⁷F₁磁偶极跃迁和⁵D ₀→⁷F₂电偶极跃迁。研究了Eu³⁺浓度对荧光粉发光性能的影响, 结果表明,随着Eu³⁺浓度的增 加,发光强度先增加后减小,最佳掺杂量为0.03,而对试样的色坐标 几乎没有影响;该系列荧光粉浓度淬灭机理为电偶极–电偶极(d-d)相互作用。     

红色荧光粉YF3:Eu3+,Gd3+的制备及发光性能

采用水热法合成了YF₃:xEu³⁺和YF₃:0.14Eu³⁺,0.08Gd³⁺系列荧光粉。通过X射线衍 射(XRD)、 扫描电子显微镜(SEM)、光电子能谱(EDS)、光致发光(PL)和长余辉光谱分别对样品的物相、 结构、形貌、 表面元素、PL和荧光寿命进行了表征。XRD检测表明,合成的样品属正交晶系。ED数据验 证了合成样品的表面元素组分。PL光谱测试表明,YF₃:xE u³⁺的激发光谱由200～300nm的宽带和Eu³⁺ 的系列窄带激发峰组成,YF₃:0.14Eu³⁺,0.08Gd³⁺的 激发光谱由200～300n m的宽带和Eu³⁺,Gd³⁺的系列窄带 激发峰组成。在319nm紫外光激发下,测得YF₃:xEu³⁺ 材料的发射光谱为一个多峰谱,主峰位于593,3nm。 当Eu³⁺掺杂物质的量的浓度大于14%时,出现了浓度猝灭现象。在319nm紫外光激发下,YF₃:0.14Eu³⁺, 0.08Gd³⁺的发射光谱出现Eu³⁺的⁵D₀→⁷F₁ (593nm,橙光)、⁵D₀→⁷F₂(613nm,红光)跃迁发光峰,此时,Gd³⁺ 的掺杂能增强Eu³⁺的发光。通过色坐标分析可知,当激发波长为374nm时,YF₃: 0.14Eu³⁺的色坐标为 (0.337,0.239),是很好的红色发光粉。对YF ₃:xEu³⁺和YF₃:0.14Eu3+ ,0.08G d³⁺的荧光衰减曲线的拟合证实,存在Gd³⁺→Eu³⁺的能量传递。     

Ce3+对掺Er3+碲铌锌钠玻璃光谱性质的影响

用高温熔融法制备了摩尔组分百分比为75TeO₂- 10Nb₂O₅-10ZnO-5Na₂O-0.5Er₂O₃-xCe₂O₃(x=0.00、0.25、 0.50、0.75、1.00)的碲酸盐玻璃样品。测量了玻璃样品的吸收光谱、上转换 光谱、拉曼光谱和 荧光光谱。结合Judd-Ofelt(J-O)理论计算了玻璃样品的强度参数Ω_t(t=2、4、6)、自发辐射跃迁几率A、荧光分支比β和辐射寿命 τrad,并用McCumber理论计算得到了Er³⁺的受激发射截面。比 较了玻璃样品中Er³⁺的放大器带宽 品质因子(σpeak_e×FWHM)和增 益品质因子(σpeak_e×τm),分 析了Er³⁺/Ce³⁺间能量转移(ET)机 理以及Ce³⁺对上转换发光的抑制作用。研究表明,适量Ce³⁺的引入对于掺Er ³⁺碲铌锌钠玻璃的光谱特性有一定的提高作用。     

YPO4:Dy3+,Eu3+荧光粉的水热合成及白光发射

采用水热法,合成了YPO₄:xDy³⁺,0.06Eu³⁺系列荧光粉。通过X射线衍射(XRD )、扫 描电子显微镜(SEM)、电子散射能谱(EDS)、光致发光(PL)谱和长余辉光谱,分别对样品的物 相、结构和PL进行了表征。 XRD检测表明,合成的样品属四方晶系;荧光光谱测试表明,在234nm紫外光激发下, YPO₄:xDy³⁺,0.06Eu³⁺的 发射光谱呈现Eu3+ 的⁵D₀→⁷F₁(592nm,橙光)和 ⁵D₀→ ⁷F₂(618nm,红光) 的发光峰;而在354nm的激发波长下,YPO₄:0.06Dy³⁺,0.06Eu³⁺的发射光谱 呈现Dy³⁺的4F9/2→⁶H15/2(486nm、蓝 光)和⁴F9/2→⁶H13/2(575nm、黄光)的发光 峰,以及Eu³⁺的⁵D₀→⁷F₁(592nm、 橙光)和⁵D₀→⁷F₂(619nm、红光 )的发光峰。对荧光 衰减谱的双参数拟合证实了Dy³⁺→Eu³⁺能量 传递的存在。色坐标图显示,在234nm紫外光激发下,YPO₄:0.05Dy ³⁺,0.06Eu3+ 是很好的近紫外光激发下的白色荧光粉。     

OPTICAL EFFECTS AND MICROSTRUCTURE OF BURIED INSULATOR LAYER FORMED BY O+ AND N+ CO-IMPLANTATION

 The microstructure and optical properties of a buried layer formed by O~+(200 keV,1.8×10~(18)/cm~2)and N~+(180 keV,4×10~(17)/cm~2)co-implantation and annealed at 1200℃ for 2 h have been investigated by Auger electron,IR absorption and reflection spectroscopic measurements.The results show that the buried layer consists of silicon dioxide and SiO_x(x< 2) and the nitrogen segregates to the wings of the buried layer where it forms an oxynitride.By detail theoretical analysis and computer simulation of the IR reflection interference spectrum,the refractive index profiles of the buried layer were obtained.     

Er3+、Eu3+双掺杂LaOF荧光粉的光学性能研究及防伪应用

有机发光材料可能对人体或环境造成影响,除此之外还有生产成本高、发光易淬灭、发光强度与颜色不易于控制的缺点,因此探索性能优越的稀土发光材料并寻找其应用价值是具有重要意义的。本文基于水热辅助固相法制备出Er³⁺、Eu³⁺离子共掺杂LaOF荧光粉,通过X射线衍射仪(X-ray diffractometer, XRD)、扫描电镜(scanning electron microscope, SEM)和荧光分析仪对不同Er³⁺掺杂浓度下的LaOF∶Eu³⁺荧光粉体的相组成、粒径尺寸、形貌及荧光光谱进行表征与分析。结果表明：在900℃的温度下煅烧,物相由前驱体LaF₃转变为四方相LaOF,且随着Er³⁺掺杂浓度的升高,在365 nm与393 nm波长激发下均呈现出多色可调谐的发光特性,其中365 nm激发下呈现自橙色光向黄色光的转变,而在393 nm光辐射下则由橙色光向品红色光过渡。将Er³⁺、Eu³⁺共掺杂LaOF荧光粉制成...     

水解工艺Yb3＋/Al3＋共掺石英玻璃的研制及特性表征

利用四氯化硅(SiCl₄)水解掺杂法结合高 频等离子体粉末熔融技术制备了Yb3＋/Al3＋共掺石英玻璃,并利用 X射 线衍射(XRD)、傅里叶变换红外(FTIR)光谱分析和热膨胀分析等对所制备玻璃样品的结 构特性、物理特性和光谱特 性进行了表征。结果表明,制备的Yb3＋/Al3＋共掺石英玻璃的密度和折 射率值与纯石英玻璃相接近,并且呈现出 较好的玻璃态,其热膨胀系数为2.87×10－6,具有较好的Yb3＋和Al 3＋掺杂均匀性,以及Yb3＋典型的吸 收特性和发射特性,表明采用本文方法制备的Yb3＋/Al3＋共掺石英玻璃 已具备成为大功率激光材料的潜质。     

Photoelectrochemical performance of La3+-doped TiO2

La-doped TiO₂ thin films on titanium substrates were prepared by the sol-gel method with titanium tetrachloride as a precursor and La₂O₃ as a source of lanthanum. The heat-treatment temperature dependence of the photoelectrochemical performance of the La-doped TiO₂ film in 0.2 mol/L Na₂SO₄ was investigated by the Mott-Schottky equation, electrochemical impedance spectroscopy, and the open-circuit potential test. The results from the Mott-Schottky curves show that the obtained films all were n-type semiconductors, and the film at 300 ℃ had the highest conduction band position and the widest space charge layer. The electrochemical impendence spectroscopy (EIS) tests of the 300 ℃ film decreased most during the change from illuminated to dark. The potential of the La-TiO₂ thin film electrode was the lowest after the 300 ℃ heat treatment. The open-circuit potential indicated that the photoelectrical performance of the La-TiO₂ films was enhanced with the addition of the La element and the largest decline (837.8 mV) in the electrode potential was achieved with the 300 ℃ heat treatment.