Efficient phosphors for mercury-free fluorescent lamps

用于无汞荧光灯的高效荧光粉

• 批准号: 12650817
• 负责人: YAMAMOTO Hajime
• 金额: $ 0.64万
• 依托单位: Tokyo University of Technology
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 2000
• 资助国家: 日本
• 起止时间: 2000 至 2002
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-12650817/
• 关键词: Mercury-free lamp; Vacuum ultraviolet; Phosphor; Rare-earth ion; Quantum efficiency; Energy transfer; Non-linear luminescence; 正燐酸塩; ホウ酸塩; quantum cutting; SrTiO_3; 不純物添加; 結晶性改善

[I]Efficient phosphors were surveyed to convert VUV light of 172nm wavelength obtained from Xe excimers to visible light. In 2001, we investigated feasibility of quantum cutting processes in stable oxides, specifically rare-earth orthophosphates. The results showed that nonradiatative relaxation from a high-energy excited level of a rare-earth ion and energy transfer between rare-earth ions in the UV region can reduce the probability of the quantum cutting. However, energy transfer from Pr3+ or Tm3+ to Gd3+ leads to efficient Gd3+ luminescence line at 312nm, which can be applied to lamps, which activate photoactive catalysis. This phenomena result from simple electronic configurations of Pr3+ or Tm3+, which have two 4f electrons or holes.[II]In 2002, we investigated materials excited by energy transfer from a host to an activator ion.(1)Substitution of Y by Gd in red-emitting YAIO3:Eu3+ gives rise to 30% increase in efficiency under 172nm light excitation. This remarkable effect result … More s from a red shift of the absorption edge of the host crystal by Gd substitution. We also developed a synthesis method to provide a single-phase material of high efficiency, which uses theta alumina as a starting material and firing temperature as high as 15000.(2)In efficient red phosphor, SrTiO3:Pr3+, Al, energy is provided from the bound exciton to Pr3+.This work has shown that energy overlap between the fundamental absorption band of the host and 4f-5d absorption band of Pr3+ is correlated with the luminescence efficiency.[III]Bright warm-white emission was discovered by cathode-ray excitation of rugged powder layers of insulater materials. This emission appears above the threshold electron-beam current and drastically increases in intensity with an increase in the beam-current density. The lowest threshold so far obtained is 0.02mA under 25kV electron excitation with a beam diameter of about 0.3mm. This emission may be a candidate of new non-mercury light source if the threshold can be further decreased. Less

[1]利用高效荧光粉将Xe准分子获得的172nm波长的VUV光转换为可见光。2001年，我们研究了稳定氧化物，特别是稀土正磷酸盐的量子切削工艺的可行性。结果表明，稀土离子的高能激发能级的非辐射弛豫和稀土离子在紫外区的能量转移可以降低量子切割的概率。然而，从Pr3+或Tm3+到Gd3+的能量转移导致Gd3+在312nm的高效发光线，可以应用于灯，从而激活光活性催化。这种现象是由Pr3+或Tm3+的简单电子构型引起的，它们有两个4f电子或空穴。[II] 2002年，我们研究了从宿主到激活离子的能量转移所激发的材料。(1)在172nm光激发下，发光YAIO3:Eu3+用Gd取代Y可使效率提高30%。这一显著的效应导致Gd取代使主晶体的吸收边发生了红移。我们还开发了一种合成方法，以theta氧化铝为起始材料，烧成温度高达15000℃，提供了一种高效率的单相材料。(2)在高效红色荧光粉SrTiO3:Pr3+， Al中，能量由束缚激子提供给Pr3+。研究表明，宿主的基吸收带与Pr3+的4f-5d吸收带之间的能量重叠与发光效率相关。[III]通过阴极射线激发，在绝缘体材料的凹凸不平的粉末层中发现了明亮的暖白色发射。这种发射出现在电子束电流的阈值以上，并随着电子束电流密度的增加而急剧增加。目前获得的最低阈值为0.02mA，在25kV电子激发下，束径约0.3mm。如果阈值可以进一步降低，这种发光可能是新的无汞光源的候选光源。少

项目成果

Shinji Okamoto, Hajime Yamamoto: "Emission from BaTiO_3:Pr^<3+> Controlled by Ionic Radius of Added Trivalent Ion"Journal of Applied Physics. 91巻8号. 5492-5494 (2002)

Shinji Okamoto、Hajime Yamamoto：“由添加三价离子的离子半径控制的 BaTiO_3:Pr^<3+> 的发射”应用物理学杂志，第 91 卷，第 8 期。5492-5494 (2002)

Y.Sato, S.Okamoto, T.Kumagai, H.Yamamoto, S.Tanaka: "Energy Transfer between Gd^<3+> and Other Rare Earth Ions in the VUV Region"Extended Abstracts, The 1^<st> Int. Conf. on the Science and Technology of Emissive Displays and Lighting. 33-36 (2001)

Y.Sato、S.Okamoto、T.Kumagai、H.Yamamoto、S.Tanaka：“VUV 区域中 Gd^<3> 和其他稀土离子之间的能量转移”扩展摘要，第 1^<st> Int。

H.Yamamoto, M.Mikami, S.Nakamura: "Nonlinear cathodoluminescence from insulators"Journal of Luminescence. 102-103. 782-784 (2002)

H.Yamamoto、M.Mikami、S.Nakamura：“绝缘体的非线性阴极发光”发光杂志。

熊谷 高梓, 佐藤 裕二, 山元 明, 国本 崇: "紫外領域におけるGd3+と他の希土類イオン間のエネルギー伝達"電子情報通信学会技術研究報告 (TECHNICAL REPORT OF IEICE). 2001-124. 139-144 (2002)

Takazusa Kumagai、Yuji Sato、Akira Yamamoto、Takashi Kunimoto：“紫外区 Gd3+ 和其他稀土离子之间的能量转移” IEICE 技术报告 139-144 (2002)。

Y.Sato, T.Kumagai, S.Okamoto, H.Yamamoto, S.Tanaka: "Energy Transfer between Gd3+ and Other Rare earth Ions in GdP04 under Vacuum UV Excitation"Japanese Journal of Applied Physics. (to be published). (2004)

Y.Sato、T.Kumagai、S.Okamoto、H.Yamamoto、S.Tanaka：“真空紫外激发下 Gd3 和 GdP04 中其他稀土离子之间的能量转移”日本应用物理学杂志。