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A series of Nb5+ codoped red long afterglow phosphors CaTi1 xNbxO3:Pr03.+002 (0 ≤ x ≤ 0.05) is prepared by a solid state reaction method. Their photoluminescence, phosphorescence and thermoluminescence are investigated. The results indicate that codoping Nb5+ can improve the photoluminescence and phosphorescence property of CaTiO3:Pr3+ significantly. When 3-mol% Nb5+ is codoped, the emission intensity of CaTiO3:Pr3+ is enhanced twice, while the afterglow time is extended from 10 min to about 40 min. Thermoluminescence results reveal that the trapping level of CaTiO3:Pr3+ is reduced from 0.82 eV to 0.62 eV by codoping Nb5+. The effect of Nb5+ doping on enhancing the photoluminescence intensity and afterglow time of CaTiO3:Pr3+ is discussed. 相似文献
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This paper reports that the green phosphor BaAl11.9O19:0.1Mn2+ is prepared by a flux assisted solid state reaction method.The effect of flux systems on the crystal structure,morphology and luminescent properties of the phosphor are studied in detail.The samples are characterized by the application of x-ray diffraction patterns,scanning electron microscopy patterns,luminescent spectra and decay curves.The results show that a pure phase BaAl12O19 can be achieved at the firing temperature above 1300℃ by adding the proper flux system,the firing temperature is reduced at least 200℃ in comparison with the conventional solid state reaction method.Maximum photoluminescence emission intensity is observed at 517 nm for(AlF3+Li2CO3) flux system under vacuum ultraviolet region(147 nm) excitation.The photoluminescence emission intensity and the decay time of these phosphor is found to be more superior to that of the corresponding sample prepared by the conventional solid state reaction method implying the suitability of this route for the preparation of display device worthy phosphor materials. 相似文献
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用燃烧法成功合成了Zn2 -xSiO4∶xMn(0≤x≤ 0 .10 )粉末样品并表征了其发光特性。XRD测量结果表明 ,在 6 0 0℃下燃烧数分钟、90 0℃以上进行热处理 4h后 ,所得样品为单相Zn2 -xSiO4∶xMn(0≤x≤ 0 .10 ,Willemite)。监控 5 2 5nm发射 ,测得Zn2 -xSiO4∶xMn(0 相似文献
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溶胶-凝胶法制备MgF2包覆BaMgAl10O17:Eu荧光粉及其发光特性 总被引:6,自引:1,他引:5
用溶胶-凝胶法在等离子显示屏(PDP)用蓝色荧光粉BaMgAl10O17:Eu(BAM)的表面上成功地包覆了MgF2膜,并研究了其发光与热衰减特性。XPS和SEM结果表明BAM荧光粉颗粒表面上形成了MgF2包覆膜。对包覆样品和未包覆样品的发光特性研究表明:在254nm激发下,最佳包覆量为0.2%(质量比),其在600℃热处理30min后包覆样品的发光强度比未包覆样品的发光强度约高12%。在147nm激发下,最佳包覆量为0.5%,其在600℃热处理30min后的发光强度比未包覆样品的发光强度高15%。这表明对BAM荧光粉进行表面包覆MgF2可以有效地稳定荧光粉的发光性能。这一结果不仅对提高PDP性能有重要意义,而且对开发无汞荧光灯用荧光粉等也具有指导意义。 相似文献
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Photoluminescence degradation mechanism of BaMgAl10O17:Eu2+ phosphor by vacuum ultraviolet irradiation
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<正>A real high power vacuum ultraviolet light source is applied to the investigation on the vacuum ultraviolet irradiation degradation of BaMgA10O17:Eu2+ phosphor.The degradations of emission intensity and color quality of the sample are clearly observed after irradiation.It reveals that the oxidation of Eu2+ during irradiation is partly responsible for the degradations.The excitation and absorption spectra show that some traps generated during irradiation have negative influence on the luminescence of sample and these traps have been identified as positively charged oxygen vacancies by positron annihilation.The investigations on host emission and decay curve further confirm that these oxygen vacancies are involved in the perturbation of energy transfer from the host to Eu2+ and finally result in the degradation. 相似文献
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用水热法制备的YVO4:Eu3+分别在400~800℃下进行热处理,研究了所得样品的结构及其发光性能。实验结果表明:所得样品都为单相结构,随着热处理温度的升高,样品的结晶度变好,颗粒变大。在紫外光谱范围,YVO4:Eu3+的激发光谱由VO43-的吸收带和Eu3+的电荷迁移带组成。在真空紫外(VUV),激发光谱由基质吸收,Y3+、O2-的电荷迁移带组成。发射光谱均为Eu3+的5D0→7FJ(J=1,2,4)跃迁。紫外和真空紫外激发下,样品的发光强度比未经过热处理的样品有显著增强,归因于样品的结晶度的提高和OH-、VO43-等发光猝灭离子的去除。 相似文献
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Photoluminescence properties of Y0.75-xGdxAl0.10BO3:Eu3+0.10, 0.05R3+ (R= Sc, Bi) (0.00≤x≤0.45)
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Y$_{0.75 -
x}$GdxAl0.10BO$3:Eu$^{3+}0.10, 0.05R3+
($R$=Sc, Bi) ($0.00 ≤ x ≤ 0.45$) powder samples are prepared
by solid-state reaction and their luminescence properties are
investigated. With the replacement of Y3+$ ions by Sc3+$
(or Bi3+)$ and Gd3+$ ions in (Y,Al)BO$3:Eu, the
intensities of emission at 254 and 147~nm are remarkably improved,
because Sc3+$ ions can absorb UV light and transfer the energy
to Eu3+$ ions efficiently. Moreover, Gd3+$ and Bi$^{3 +
}$ ions act as an intermediate ``bridge' between the sensitizer and
the activator (Eu3+)$ in energy transfer to produce light in
the (Y, Gd)BO$3:Bi3+$, Eu3+$ system more effectively.
After doping an appropriate concentration of Gd3+$ into
Y$_{0.50}$Gd$_{0.25}$Al0.10BO$3:Eu3+_{0.01}$,
Bi$^{3+}_{0.05}$, the emission intensity reaches its maximum, which
is nearly 110{\%} compared with the red commercial phosphor
(Y,Gd)BO$3:Eu and better chromaticity coordinates (0.650, 0.350)
are obtained. 相似文献