体育馆LED显示屏的光色参数测量

该文主要通过体育场馆中LED显示屏的测量实例,介绍了广州亚运会网球场等体育场馆中LED显示屏的亮度、对比度、白场色品坐标、色温、亮度均匀度、基色主波长和视角等重要参数的检测方法方案,总结了体育场馆LED显示屏检测经验,并对相应标准提出了一些建议。     

白光LED用红色荧光粉Li(MoO4)2∶Eu3+的制备及表征

以H3BO3助熔剂采用高温固相反应法制备了LiMo2O8∶Eu3+红色荧光粉.通过XRD、SEM及激发和发射光谱对样品进行了研究,结果表明,引入助熔剂为3 wt％时样品具有好的结晶和优良的光谱性质;光谱测量的结果表明,在近紫外、蓝光激发下,能发射出615nm的红光,具有较高的色纯度.因此,可作为目前已商品化的白光LED...     

白光LED用红色荧光粉Li(MoO_4)_2:Eu~(3+)的制备及表征

以H3BO3助熔剂采用高温固相反应法制备了LiMo2O8∶Eu3+红色荧光粉。通过XRD、SEM及激发和发射光谱对样品进行了研究,结果表明,引入助熔剂为3 wt%时样品具有好的结晶和优良的光谱性质;光谱测量的结果表明,在近紫外、蓝光激发下,能发射出615nm的红光,具有较高的色纯度。因此,可作为目前已商品化的白光LED的红色补偿荧光粉,也可作为近紫外LED和三基色荧光粉组合型白光器件的红色荧光粉的候选材料。     

高等植物叶片色域的理论研究

利用叶绿素和类胡萝卜素的经典吸收光谱以及植物叶片中不含色素的其他物质成分的光谱，分别求得其在CIE1931色品图中的理论坐标，并根据色度学中的加法混色原理确定出高等植物叶色的理论域范围。实验数据与理论相吻合。     

一种远距离可变焦光谱测量装置设计

设计研制了一种远距离可变焦的光谱测量装置.该装置由望远变焦成像系统和光谱色度计构成,具有对目标光源望远瞄准和变焦的功能.试验结果表明该装置实现了远距离光谱和色品坐标的测量;其色品坐标测量误差为0.0040,相对扩展不确定度为2.1％.     

等离子体显示板真空紫外荧光测试系统

设计等离子体显示板(PDP)真空紫外荧光测试系统来测评PDP荧光粉的特性。系统通过巧妙设计测试腔,模拟PDP放电单元,为激发PDP荧光粉发光提供所需要的较强真空紫外线,使系统能够分析出荧光粉的光谱功率分布、发光亮度、带宽、发射谱线主峰波长、色品坐标、颜色纯度和主波长等各种光学特性。实验结果数据表明,该系统的可重复性好、精度高,为研制高质量的等离子体显示板提供了依据。     

用InGaN蓝光LED与YAG荧光粉制造自然白光LED

报导了用国内自行研制的InGaN/GaN蓝光发光二极管（LED）与钇铝石榴石（YAG）荧光粉结合而得的白光发光二极管（W－LED），在室温，正向电压3．5V，正向电流20mA时，W－LED轴向亮度为1cd,CIE色坐标为（0．31，0．38），接近纯白色（0．33，0．33）。     

三原色染色法测定棉麻纤维混纺比初探

为减少纤维成分棉麻含量检验工作的强度,通过三原色染色法,研究三原色染色棉麻纤维的色度学参数数据与棉麻含量的线性关系,得出色度坐标x的数据与棉含量的线性关系较好。建立三原色染色法测定棉麻混纺比的方法,与标准法显微投影法进行比对,结果非常相近,满足快速测定棉麻纤维混纺比的要求。     

光源颜色特性的测量及计算方法

随着新型光源的不断产生，对光源颜色特性参数的计量也越来越多，如何准确评价光源的色温、色坐标、显色指数、色容差、光效率及红色比等参数是十分重要的。在本套测量系统中，光源的光谱功率分布是通过比对的试验方法测量得出的，而颜色参数则是通过光源的光谱功率分布计算得出来的。本文中针对如何建立光源颜色特性测量系统做了一个较为详细的介绍。     

普通照明用LED模块光色性能测试方法的研究

随着LED技术的持续发展,其检测方法和评价标准成为了世界LED产业所面临的共同挑战。该文介绍了LED模块的光强分布、光通量、光强、相关色温、显色指数、色品坐标、色品容差、平均颜色不均匀性和最大颜色不均匀性等光色性能参数的测试方法,并结合自己在检测LED模块产品检测工作中的积累,总结了LED模块相具体条件下应选用的测试方法。     

Cathodoluminescence of rare-earth-doped zinc aluminate films

Eu-, Tb-, and Tm-doped zinc aluminate (ZnAl₂O₄) thin film phosphors were prepared by the spray pyrolysis technique at an ambient pressure. The effects of preparation conditions on the cathodoluminescence properties of the films were studied. Films containing Tb³⁺ and Tm³⁺ ions exhibited green and blue cathodoluminescence, respectively. For films doped with europium, both red emission lines from Eu³⁺ and a broad blue–green emission band from Eu²⁺ were observed. The CIE (Commission Internationale de L'Eclairage) chromatic coordinates, dominant wavelength, and color purity were determined for each phosphor. The luminance and efficiency of these phosphors at a current density of 57 μA/cm² are found to be linearly dependent on the excitation voltage.     

Dy3+-doped nano-glass ceramics comprising NaAlSiO4 and NaY9Si6O26 nanocrystals for white light generation

The radiative emission properties of the Dy³⁺ ions in oxyfluoride glasses and glass ceramics have been investigated for the generation of white light. The X-ray diffraction pattern of the glass ceramics reveals the presence of NaAlSiO₄ nanocrystals along with secondary phase of NaY₉Si₆O₂₆ in the glass matrix after a suitable thermal treatment of the pristine glasses. Intense white light emission has been observed when the samples are excited with 350 nm light. Yellow to blue emission intensity ratios and chromaticity color coordinates have been determined from the visible luminescence spectra. All color coordinates are found to lie in the white region of the chromaticity color diagram proposing the suitability of the present studied materials for color display devices.     

Optical properties of Eu<Superscript>3+</Superscript> activated SrLa<Subscript>2</Subscript>O<Subscript>4</Subscript> red-emitting phosphors for WLED applications

The SrLa_2?xO₄:xEu³⁺ phosphors are synthesized through high-temperature solid-state reaction method at 1473 K with various doping concentration. Their phase structures, absorption spectra, and luminescence properties are investigated by X-ray diffraction (XRD), UV–Vis spectrophotometer and photoluminescence spectrometry. The intense absorption of SrLa_2?xO₄:xEu³⁺ phosphors have occurred around 400 nm. The prominent luminescence spectra of the prepared phosphors exhibited bright red emission at 626 nm. The doping concentration 0.12 mol% of Eu³⁺ is shown to be optimal for prominent red emission and chromaticity coordinates are x?=?0.692, y?=?0.3072. Considering the high colour purity and appropriate emission intensity of Eu³⁺ doped SrLa₂O₄ can be used as red phosphors for white light emitting diodes (WLEDs).     

Variations of color with alloying elements in Pd-free Au–Pt-based high noble dental alloys

The effects of alloying addition of a small amount of base metals (In, Sn, Fe, Zn) on color variations in Pd-free Au–Pt-based high noble dental alloys were investigated in terms of rectilinear and polar color coordinates. The ternary Au–Pt–X (X = In, Sn, Fe, Zn) and quaternary Au–Pt–In–Y (Y = Sn, Fe, Zn) alloys were prepared from high purity component metals. The amount of alloying base metals, X and Y, were restricted up to 2 at.%. The alloying addition of a small amount of Fe, In, Sn, to a binary Au–10 at.% Pt alloy (referred to as AP10) effectively increased chroma, C^*. On the other hand, the addition of Zn to the parent alloy AP10 did not change color coordinates greatly. The increase in chroma in the present Au–Pt-based high noble alloys was attributed to the increase in the slope of spectral reflectance curve at its absorption edge near 515 nm. It was found that the addition of a small amount of Fe to the parent alloy AP10 markedly increased lightness, L^*, and the addition of Sn gave a very light tint of red to the parent alloy. Although red–green chromaticity index a^* contributed to chroma to some extent, contribution of yellow–blue chromaticity index b^* was much greater in determining chroma in this Pd-free Au–Pt-based multi-component alloys. The present results are expected to be valuable in case color is to be taken into account in designing Pd-free Au–Pt-based high noble dental alloys.     

Luminescence properties of (Ca,Y)-α-SiAlON:Eu phosphors

(Ca,Y)-α-SiAlON:Eu phosphors for white LED lamps were prepared and their luminescence properties were investigated. A red shift of emission wavelength occurred when Ca was partially replaced by Y. Raising the sintering temperature also caused the red shift. As a result, the peak emission wavelength varied from 585 nm to 608 nm, with increasing of the Y content and the sintering temperature, and therefore the chromaticity range of (Ca,Y)-α-SiAlON phosphors extended to longer wavelength by these results. The corresponding correlated color temperature (CCT) of white LED lamps using (Ca,Y)-α-SiAlON:Eu also extended to the temperature as low as 1700 K.     

Photoluminescence and energy transfer study of Er3+ and Dy3+ codoped tellurite glasses

Photoluminescence properties of the Er(3+)-Dy3+ codoped tellurite glasses were studied by absorption and visible emission spectra, which revealed luminescence bands of both Er3+ and Dy3+ when pumping with the wavelength of 325 nm. The concentration quenching occurred as Dy3+ concentration increased beyond 3 mol%. The dependence of Er3+ characteristic emission on Dy3+ concentration indicated energy transfer process between Er3+ and Dy3+. The chromaticity coordinates of these glasses are close to white light, which implies that these glasses might be potential candidates for white lighting through an appropriate combination.     

基于双蓝光有源区激发YAG:Ce荧光粉的高显色性白光LED

在(0001)蓝宝石衬底上利用金属有机化学气相沉积系统,分别生长含有p-AlGaN电子阻挡层和反对称n-AlGaN层的双蓝光波长发射的InGaN/GaN混合多量子阱发光二极管(LED)。结果发现,与传统的具有p-AlGaN电子阻挡层的双蓝光波长LED相比,这种n-AlGaN层能有效改善电子和空穴在混合多量子阱活性层中的分布均匀性和减少电子溢出,并减弱双蓝光发射光谱对电流的依赖性。此外,基于这种双蓝光波长发射的芯片与YAG:Ce荧光粉封装成白光LED能实现高显色性的白光发射,在20 mA电流驱动下,6500 K色温时显色指数达到91,而基于单蓝光芯片的白光LED显色指数只有75。     

White Light Emission Characteristics of Tb~(3+)/Sm~(3+) Co-Doped Glass Ceramics Containing YPO_4 Nanocrystals

The Tb~(3+)/Sm~(3+) single-doped and co-doped glasses and glass ceramics containing YPO_4 nanocrystals have been synthesized by melt quenching method. The structural and luminescent properties of these glass specimens were investigated. Under 375 nm wavelength excitation, the emission spectra combined with blue, green and red bands were observed, which achieved the white light emission. Moreover, the energy transfer between Tb~(3+) and Sm~(3+)ions was validated by decay lifetime measurement and energy level diagram.The color coordinates(x = 0.333, y = 0.333), correlated color temperature(5595 K) and the color rendering index(Ra = 80.5) indicated that the glass ceramics were considered to be good lighting source. Hence,the YPO_(4-) based Tb~(3+)/Sm~(3+) co-doped glass ceramics can act as potential matrix materials for white lightemitting diodes under ultraviolet excitation.