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一种新颖的白光LED荧光粉测量系统和分析方法(英文) 总被引:2,自引:1,他引:1
为获得高效率的白光LED,得到荧光粉和芯片的最佳匹配,本文提出了一种新颖的白光LED荧光粉测量系统和分析方法.该方法根据荧光粉测量原理,采用单色光激发荧光粉,获得荧光粉的激发光谱特性.由单波长激发的光谱组合可以得到荧光粉的三维光谱特性,荧光粉光谱与LED芯片光谱匹配可以模拟白光LED光谱.分析了荧光粉在单波长及光谱激发条件下的效率.实验结果表明,该测量系统和分析方法可以确定荧光粉和兰光LED芯片的最佳匹配,从而为获得高效率白光LED奠定了良好的基础. 相似文献
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白光LED用稀土红色荧光粉的研究进展 总被引:4,自引:1,他引:3
白光LED具有低压、低功耗、高可靠性和长寿命等一系列优点,是一种符合环保和节能的绿色照明光源。现阶段制造高显色指数、低色温,大功率白光LED是白光LED发展的总体趋势。而红色荧光粉性能对白光LED的显色指数及色温的影响极其显著。本方法着重介绍和评述了白光LED用红色荧光粉硫化物、氮化物、钼酸盐和钨酸盐等几大主要体系的发光性质及最新研究成果和发展现状,并对白光LED用荧光粉的发展进行了展望。 相似文献
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O. V. Kucherova V. I. Zubkov E. O. Tsvelev I. N. Yakovlev A. V. Solomonov 《Inorganic Materials》2011,47(14):1574-1578
On the basis of the designed complex of low-temperature admittance spectroscopy, the electron spectrum of semiconductor light
emitting diode (LED) heterostructures with InGaN/GaN multiple quantum wells was investigated. The features of the construction
of the measuring complex, as well as the technique of measurements of semiconductor nanoheterostructures and processing of
admittance spectra, are presented. 相似文献
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M. Kottaisamy P. Thiyagarajan J. Mishra M.S. Ramachandra Rao 《Materials Research Bulletin》2008,43(7):1657-1663
Gadolinium or lanthanum co-doped (0.5 mole) yttrium aluminum garnet doped with cerium phosphors were synthesized by a citric acid gel method and the effect of co-dopants on the structural and luminescent properties were studied. A significant peak shift in the photoluminescence spectra of yttrium aluminum garnet doped cerium was observed from 535 to 556 and 576 nm for gadolinium or lanthanum co-doped phosphors, respectively. The color tuned phosphor were blended with yttrium aluminum garnet doped cerium which showed a considerable improvement in the Commission International De Eclairage chromaticity co-ordinate values of gallium nitride based blue light emitting diode pumped white light. White light emitted from yttrium aluminum garnet doped cerium shows a Commission International De Eclairage value of (0.229, 0.182) whereas the yttrium aluminum garnet doped cerium phosphor blended with gadolinium or lanthanum co-doped phosphor shows (0.262, 0.243) and (0.295, 0.282), respectively. These results demonstrate the possibility to use these phosphor blends to enhance the white light generation in the field of white-light emitting diode solid-state lighting. 相似文献
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Well dispersed and homogeneous Y2O2S:Sm3+ hollow submicrospheres were successfully achieved by a templatefree solvothermal method combining with a postcalcining process.The crystalstructure and particle morphology were investigated by the X-ray diffraction(XRD),Fourier transform infrared(FT-IR) spectra,scanning and transmission electron microscopy(SEM and TEM),respectively.A possible growth mechanism was proposed to reveal the formation process.Luminescence properties of the Y2O2S:Sm3+ long-lasting phosphor were analyzed by measuring the excitation spectra,emission spectra,afterglow decay curve and thermoluminescence curve.The excitation spectra indicated that the phosphor could be excited effectively by the ultraviolet-light emitting diode(UV-LED) or blue LED,and the emission spectra showed that the phosphor could emit red light from 600 to 650 nm. 相似文献
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Recent advances in organolanthanide based organic light emitting diodes have lead to the demonstration of infra-red emitting devices. A silicon based organic light emitting diode exhibiting 1.53 μm electroluminescence at room temperature has also recently been reported. Furthermore, recent work has led to a clearer understanding of the quenching mechanisms in these organolanthanide based devices and suggests that the efficiencies obtained to date can be greatly improved. 相似文献
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Magnesium and Cadmium doped ZnO nanowires were successfully grown by Chemical Vapor deposition method in a tube furnance. Photoluminescence spectra show that the band gap of ZnO nanowire has been tuned from 4.00 eV to 2.08 eV by Magnesium and Cadmium doping. Transmission Electron Microscopy and X-ray diffraction characterization analysis indicate that most of the formed nanowires are single crystalline with good quality. Zn(1-x)Cd(x)O nanowire sample was used for heterojunctional light emitting diode fabrication. Electroluminescence measurement yields a strong emission peak at 553 nm from the Zn(1-x)Cd(x)O nanowire. 相似文献
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Vertically aligned Mg alloyed ZnO nanowires were successfully grown by Chemical Vapor deposition method in a tube furnace. Structural analysis found that the MgZnO nanowires are with single crystalline without phase separations. The atomic ratio of Mg/O in the nanowire was determined to be approximately 15%. Photoluminescence spectra show that the band gap of ZnO nanowire was tuned to approximately 3.6 eV due to Mg incorporation. N-type MgZnO nanowires/p-type GaN was used for heterojunctional light emitting diode fabrication. Electroluminescence measurement yielded ultraviolet emission peaks, which includes a deep ultraviolet at approximately 340 nm. The results suggest that successful Mg alloying in ZnO nanowires was achieved and is promising for deep ultraviolet devices. 相似文献
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Abstract A detailed comparison is made between the experimentally determined photonic band structure and the measured angle-dependent emission spectra of textured, metal-clad microcavities containing the light-emitting polymer MEH-PPV. Transmittivity measurements were made over a range of optical frequency and in-plane wavevector in order to obtain a detailed map of the dispersion of the waveguide modes supported by the textured cavities. Emission spectra were also recorded, for a large number of sample orientations, and are compared with the transmittivity maps. It is found that the band structure strongly influences the wavelength of the peaks in the emission spectra, and that the periodic texture leads to the generation of Bragg-scattered emission. The positions of these spectral peaks in both frequency and in-plane wavevector are found to agree very well with the positions of peak transmittivity of the cavities. The emission spectra also show clear evidence of the photonic band gaps formed by the periodic texture. The importance of these findings for light-emissive devices such as the light emitting diode is discussed. 相似文献