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Hydrothermal Synthesis and Vacuum Ultraviolet-Excited Luminescence Properties of Novel Dy^3+-doped GdPO4 White Light Phosphors 下载免费PDF全文
Novel Dy^3+-doped GdPO4 white light phosphors with a monoclinic system are successfully synthesized by the hydrothermal method at 240℃. The strong absorption at around 147nm in the excitation spectrum is assigned to the host absorption. It is suggested that the vacuum ultraviolet excited energy is transferred from the host to the Dy^3+ ions. The f - d transition of the Dy^3+ ion is observed to be located at 182nm, which is consistent with the calculated value using Dorenbos's expression. Under 147nm excitation, Gd0.92PO4:0.08Dy^3+ phosphor exhibits two emission bands located at 572 nm (yellow) and 478 nm (blue), which correspond to the hypersensitive transitions ^4 F9/2-^6 H13/2 and ^4 F9/2-^6 H15/2. The two emission bands lead to the white light. Because of the strong absorption at about 147nm, Gd0.92PO4:0.08Dy^3+ under vacuum ultraviolet excitation is an effective white light phosphor, and has promising applications to mercury-free lamps. 相似文献
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选取典型的助熔剂,利用助熔剂法制备了节能灯用(Ce0.67,Tb0.33)MgAl11O19绿色荧光粉,并对其发光性能进行了对比测试。研究了各单一或复合助熔剂对(Ce0.67,Tb0.33)MgAl11O19荧光粉的发光亮度及颗粒形貌的作用及影响,并找到了最佳复合助熔剂组分为0.2%H3BO3+2.0%Li2CO3+2.0%AlF3(质量分数)。所制备的(Ce0.67,Tb0.33)MgAl11O19荧光粉样品具有较为规则的形貌,且发光亮度与(Ce0.67,Tb0.33)MgAl11O19现有商用粉的比值为103:100。 相似文献
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采用高温固相法在单一基质中制备了具有多模态发光特性的系列荧光粉BaGa2Si2O8∶Eu2+,Eu3+,Pr3+,掺入适量的Pr3+可显著改善荧光粉的余辉发光性能。结果表明,该系列荧光粉在254 nm或365 nm的光激发下,具有不同颜色的光致发光和余辉发光,体现出多模发光特征;同时该系列荧光粉的余辉发光还具有不同的衰减时间。根据这些发光特性,选用合适的荧光粉制作了系列发光图案。相关典型应用示例表明,该发光图案的多模发光特征可应用于发光防伪应用,而基于其差异化的余辉衰减特性,还可以设计出可动态变化的余辉发光图案,从而增加发光防伪和加密的安全层级。 相似文献
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Photoluminescence degradation mechanism of BaMgAl10O17:Eu2+ phosphor by vacuum ultraviolet irradiation 下载免费PDF全文
<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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采用高温固相法合成了发光材料Ca2GeO4 ∶Eu3+ ,并详细研究了其紫外-真空紫外发光特性. 发现并解释了Eu3+ 离子在空气中的自还原以及在不同波长激发下的颜色转换现象. Ca2GeO4 ∶Eu3+ 在163—230和301,466 nm处具有强激发带,表明Ca2GeO4 ∶Eu3+
关键词:
2GeO4 ∶Eu3+')" href="#">Ca2GeO4 ∶Eu3+
光致发光机理
空气中自还原
颜色转换 相似文献
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Photoluminescence and persistent luminescence properties of non-doped and Ti4+-doped Mg2SnO4 phosphors 下载免费PDF全文
Mg2SnO4 exhibits green photoluminescence and persistent luminescence, which originate from oxygen vacancies. When Ti4+ ions were doped, an interesting Mg2SnO4:Ti4+ phosphor with bluish white photoluminescence under ultraviolet irradiation and with green persistent luminescence was first obtained. Our investigation reveals that two emission centres exist in Mg2SnO4:Ti4+. The centres responsible for the green emission are considered to be the F centres (oxygen vacancies) and the blue centres are the TiO6 complex. Trap clusters in the band gap with different depths, such as [SnMg‥—Oi″], [SnMg‥—VO·], [SnMg‥—VO×] and MgSn″, correspond to the components at 85 ℃, 146 ℃ and 213 ℃ of the thermoluminescence curve. 相似文献
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Vacuum Ultraviolet Excited Photoluminescence Properties of Novel Na3Y9O3(BO3)8:Tb^3+ Phosphor 总被引:1,自引:0,他引:1 下载免费PDF全文
The novel vacuum ultraviolet (VUV) excited Na3 Y9O3 (BO3)8:Tb^3+ (NYOB:Tb^3+) green phosphor is prepared. Strong VUV photoluminescence and high quenching concentration of Tb^3+ (20 wt%) are observed in NYOB: Tb^3+ and the strong emission are correlated with the unique layer-type structure of NYOB. All the characteristic 4 f - 5d transitions of Tb^3+ and the host absorption band in VUV region are identified in the excitation spectrum. Based on the results, the energy levels scheme of Tb^3+ in NYOB:Tb^3+ is first established. This newly developed NYOB:Tb^3+ phosphor shows excellent optical properties when compared with the commercial Zn2SiO4:Mn^2+ and would be a potential VUV-excited green phosphor. 相似文献