2003 Fiscal Year Final Research Report Summary
Growth arid properties of long-lasting phosphors stored with solar energy
| Project/Area Number |
14550037
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Applied optics/Quantum optical engineering
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| Research Institution | Gifu University2002 |
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Principal Investigator |
YAMAGA Mitsuo Gifu University, Department of Mathematical and Design Engineering, Professor, 工学部, 教授 (90159202)
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| Co-Investigator(Kenkyū-buntansha) |
KODAMA Nobuhiro Akita University, Department of Materials Science and Engineering, Professor, 工学資源学部, 教授 (90282152)
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| Project Period (FY) |
2002 – 2003
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| Keywords | long-lasting phosphorescence / Optical energy storage materials / Barium silicate crystals / Rare earth ions / Europium ions / electron-hole recombination / Self-trapped holes / Color centers |
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| Research Abstract |
UV or visible excitation for Eu^<2+:>Ba_2SiO_4 and Eu^<2+:>\Bs_3SiO_5 crystals produces broadband luminescence with peak wavelengths of 510 and 590 nm, respectively. The intensities of the long-lasting phosphorescence were measured as functions of temperature and time. The radiative decay times are distributed in the wide range of 1-10^3 seconds besides the Eu^<2+> fluorescence lifetime of 10^6 seconds. The decay curves above one second in the temperature range of 100-500 K fit t^n(n〜1). The temperature dependence of the long-lasting phosphorescene intensities integrated, in a time domain. obeys the modified Arrhenius's equation. with thermal activation energies including radiative and nonradiative decay processes. These results suggest that electrons and holes produced by UV or visible excitation move back to Eu2+ sites in the crystals through thermal hopping and/or tunneling and recombine radiatively at Eu^<2+>.
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Research Products
(12 results)
