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Efficient phosphors for mercury-free fluorescent lamps

Research Project

Project/Area Number 12650817
Research Category

Grant-in-Aid for Scientific Research (C)

Allocation TypeSingle-year Grants
Section一般
Research Field 工業物理化学
Research InstitutionTokyo University of Technology

Principal Investigator

YAMAMOTO Hajime  Tokyo University of Technology, School of Bionics, Professor, バイオニクス学部, 教授 (00247298)

Co-Investigator(Kenkyū-buntansha) OKAMOTO Shinji  Nara Institute of Science and Technology, Graduate School of Materials science, Assciate researcher, 物質創生科学科, 助手 (50324976)
MITA Yo  Tokyo University of Technology, Faculty of Engineering, Professor, 工学部, 教授 (20200040)
Project Period (FY) 2000 – 2002
Project Status Completed (Fiscal Year 2002)
Budget Amount *help
¥1,000,000 (Direct Cost: ¥1,000,000)
Fiscal Year 2002: ¥500,000 (Direct Cost: ¥500,000)
Fiscal Year 2001: ¥500,000 (Direct Cost: ¥500,000)
KeywordsMercury-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
Research Abstract

[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

Report

(4 results)
  • 2002 Annual Research Report   Final Research Report Summary
  • 2001 Annual Research Report
  • 2000 Annual Research Report
  • Research Products

    (23 results)

All Other

All Publications (23 results)

  • [Publications] Y.Sato, S.Okamoto, P.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)

    • Description
      「研究成果報告書概要(和文)」より
    • Related Report
      2002 Final Research Report Summary
  • [Publications] H.Yamamoto, S.Okamoto, H.Kobayashi: "Luminescence of rare-earth ions in perovskite-type oxides from basic research to applications"Journal of Luminescence. 100. 325-332 (2002)

    • Description
      「研究成果報告書概要(和文)」より
    • Related Report
      2002 Final Research Report Summary
  • [Publications] S.Okamoto, H.Yamamoto: "Emission from BaTiO_3 Pr^<3+> Controlled by Ionic Radius of Added Trivalent Ion"Journal of Applied Physics. 91(8). 5492-5494 (2002)

    • Description
      「研究成果報告書概要(和文)」より
    • Related Report
      2002 Final Research Report Summary
  • [Publications] S.Okamoto, H.Yamamoto: "Luminescence properties of praseodymium-doped alkaline-earth titanates"Journal of Luminescence. 102-103. 586-589 (2002)

    • Description
      「研究成果報告書概要(和文)」より
    • Related Report
      2002 Final Research Report Summary
  • [Publications] H.Yamamoto, M.Mikami, S.Nakamura: "Nonlinear cathodoluminescence from insulators"Journal of Luminescence. 102-103. 782-784 (2002)

    • Description
      「研究成果報告書概要(和文)」より
    • Related Report
      2002 Final Research Report Summary
  • [Publications] 熊谷 高梓, 佐藤 裕二, 山元 明, 国本 崇: "紫外領域におけるGd^<3+>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)

    • Description
      「研究成果報告書概要(和文)」より
    • Related Report
      2002 Final Research Report Summary
  • [Publications] Y.Sato, T.Kumagai, S.Okamoto, H.Yamamoto, S.Tanaka: "Energy Transfer between Gd^<3+> and Other Rare earth Ions in GdPO_4 under Vacuum UV Excitation"Japanese Journal of Applied Physics. (to be published). (2004)

    • Description
      「研究成果報告書概要(和文)」より
    • Related Report
      2002 Final Research Report Summary
  • [Publications] Y.Sato, S.Okamoto, T.Kumagai, H.Yamamoto, S.Tanaka: "Energy Transfer between Gd3+ and Rare earth Ions in the VUV region"Extended Abstracts, The 1st Int.Conf.On the science and Technorogy of Emissive Displays and Lighting. 33-36 (2001)

    • Description
      「研究成果報告書概要(欧文)」より
    • Related Report
      2002 Final Research Report Summary
  • [Publications] H.Yamamoto, S.Okamoto, H.Kobayashi: "Luminescence of rare-earth ions in perovskite-type oxides : from basic research to applications"Journal of Luminescence. 100. 325-332 (2002)

    • Description
      「研究成果報告書概要(欧文)」より
    • Related Report
      2002 Final Research Report Summary
  • [Publications] S.Okamoto, H.Yamamoto: "Emission from BaTiO3:Pr3+ Controlled by Ionic Radius of Added Trivalent Ion"Journal of Applied Physics. 91[8]. 5492-5494 (2002)

    • Description
      「研究成果報告書概要(欧文)」より
    • Related Report
      2002 Final Research Report Summary
  • [Publications] S.Okamoto, H.Yamamoto: "Luminescence properties of praseodymium-doped alkaline-earth titanates"Journal of Luminescence. 102-103. 586-589 (2002)

    • Description
      「研究成果報告書概要(欧文)」より
    • Related Report
      2002 Final Research Report Summary
  • [Publications] H.Yamamoto, M.MIkami, S.Nakamura: "Nonlinear cathodoluminescence from insulators"Journal of Luminescence. 102-103. 782-784 (2002)

    • Description
      「研究成果報告書概要(欧文)」より
    • Related Report
      2002 Final Research Report Summary
  • [Publications] 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)

    • Description
      「研究成果報告書概要(欧文)」より
    • Related Report
      2002 Final Research Report Summary
  • [Publications] 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)

    • Description
      「研究成果報告書概要(欧文)」より
    • Related Report
      2002 Final Research Report Summary
  • [Publications] H.Yamamoto, S.Okamoto, H.Kobayashi: "Luminescence of rare-earth ions in perovskite-type oxides : from basic research to applications"Jonurnal of Luminescence. 100. 325-332 (2002)

    • Related Report
      2002 Annual Research Report
  • [Publications] H.Yamamoto, M.Mikami, S.Nakamura: "Nonlinear cathodoluminescence from insulators"Journal of Luminescence. 102-103. 782-784 (2003)

    • Related Report
      2002 Annual Research Report
  • [Publications] Y.Sato, T.Kumagai, S.Okamoto, H.Yamamoto, S.Tanaka: "Energy transfer between Gd3+ and other rare earth ions in the VUV region"Japanese Journal of Applied Physics. 42(未定). (2003)

    • Related Report
      2002 Annual Research Report
  • [Publications] 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)

    • Related Report
      2001 Annual Research Report
  • [Publications] 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)

    • Related Report
      2001 Annual Research Report
  • [Publications] Hajime Yamamoto, S.Mitsumine, M.Ogura, S.Okamoto: "A red phosphor for low-energy electron excitation : SrIn_2O_4 : Pr^<3+> codoped with a III-group element"Proceeding Asia Display/International Display Workshop '01. 1087-1090 (2001)

    • Related Report
      2001 Annual Research Report
  • [Publications] 熊谷 高梓, 佐藤 裕二, 山元 明, 国本 崇: "紫外領域におけるGd^<3+>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)

    • Related Report
      2001 Annual Research Report
  • [Publications] S.Okamoto,H.Kobayashi & H.Yamamoto: "Effects of Al Addition on Photoluminescence Properties in Rare-Earth Ion-Doped SrTi0_3"J.Electrochem.Soc.. 147,6. 2389-2393 (2000)

    • Related Report
      2000 Annual Research Report
  • [Publications] S.Okamoto & H.Yamamoto: "Characteristic enhancement of emission from SrTi0_3 : Pr by addition of group-IIIb ions"Appl.Phys.Letters. 78,5. 655-657 (2001)

    • Related Report
      2000 Annual Research Report

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Published: 2001-04-01   Modified: 2016-04-21  

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