Yoriko Suda
;
Tsuyoshi Okuno
;
Takashi Takeda
(National Institute for Materials Science)
;
Kohsei Takahashi
(National Institute for Materials Science)
;
Naoto Hirosaki
(National Institute for Materials Science)
説明:
(abstract)Defects in phosphors affect not only luminescence intensity but also emission peak width, decay time, and afterglow. The green phosphor β-SiAlON:Eu2+ exhibits the green emission of Eu2+ at 520 nm and the blue emission of nitrogen vacancies at 460 nm in time-resolved fluorescence measurements. The decay time of the intrinsic Eu2+ transition is 0.7 us, but afterglow is detected from 50 us to 0.01 s. This afterglow decay curve is the same for the green emission of Eu2+ and the blue emission of nitrogen vacancies, suggesting that the defect levels of the nitrogen vacancies affect the Eu2+ transition. The afterglow decay curves were analyzed using the formula of the general-order kinetics, (1 + 𝑡/𝜏B)−𝑛, where 𝑛 is the decay power and 𝜏B is the decay time. This equation is generally used when analyzing afterglow on the order of seconds to hours but has not been examined systematically applied in samples with different temperatures and concentrations on the order of nanoseconds to milliseconds.The decay power 𝑛 is approximately 1 for all Eu2+ concentrations (x = 0.001 to 0.3) and undoped β-SiAlON. The decay time 𝜏B is correlated with the density of the nitrogen vacancies determined by electron spin resonance. Furthermore, the value of 𝑛 is approximately 1 for 50 us to 0.01 s and 0.3 for 1–1000 s. Thus, the luminescence mechanism of Eu2+ can be discussed by comparing 𝑛 and 𝜏B obtained form the decay curves. In addition, several different Eu2+ -doped phosphors, namely SrAl2O4:Eu2+, Dy3+, CaAlSiN3:Eu2+, and CaS:Eu2+, Tm3+, are studied.
権利情報:
キーワード: luminescence, decay curve, afterglow, phosphor, SiAlON, europium
刊行年月日: 2024-05-03
出版者: IOP Publishing
掲載誌:
研究助成金:
原稿種別: 著者最終稿 (Accepted manuscript)
MDR DOI: https://doi.org/10.48505/nims.4893
公開URL: https://doi.org/10.1088/1361-6463/ad2294
関連資料:
その他の識別子:
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更新時刻: 2025-02-07 12:30:36 +0900
MDRでの公開時刻: 2025-02-07 12:30:36 +0900
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bSiAlONdecay_revised.pdf
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