X-Ray storage luminescence of BaFCl:Eu2+ single crystals.
X-Ray storage luminescence of BaFCl:Eu2+ single crystals.
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DOI：
10.1021/jp050317r
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发表时间：
2005-06
期刊：
影响因子：
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通讯作者：
Wei Chen;N. Kristianpoller;A. Shmilevich;D. Weiss;R. Chen;M. Su
中科院分区：
文献类型：
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作者：
Wei Chen;N. Kristianpoller;A. Shmilevich;D. Weiss;R. Chen;M. Su
研究了 BaFCl:Eu2+ 单晶从室温到液氮温度下的 X 射线发光 (XL)、光致发光 (PL)、光激发光和热致发光 (TL) 的温度行为。在 XL 光谱中观察到 275、315、365、385、435 和 500 nm 处的 6 个发射，分别归因于 Cl 激子、V(k)(Cl2-)、Eu2+ 的 4f65d1 (2e(g)) --> 4f7 (8S(7/2)) 跃迁和氧空位。在 PL 和 TL 测量中观察到 315、365 和 390 nm 处的三个发射峰。这三种发射分别来自Eu2+的4f7(6I(7/2)) --> 4f7(8S(7/2))、4f7(6P(7/2)) --> 4f7(8S(7/2))和4f65d1 (2e(g)) --> 4f7(8S(7/2))的跃迁。在我们的测量中，我们观察到Eu2+的发射强度在β辐射下增加，并且没有看到任何与Eu3+离子相关的信号，这表明Eu2+离子在X射线或β辐射下可能不会被氧化为Eu3+。相反，色心、Cl 激子和氧缺陷被产生，并且在室温下稳定，它们可能在存储发光中发挥关键作用。
Temperature behaviors of X-ray luminescence (XL), photoluminescence (PL), photostimulated luminescence, and thermoluminescence (TL) were studied in BaFCl:Eu2+ single crystals from room temperature to liquid nitrogen temperature. Six emissions at 275, 315, 365, 385, 435, and 500 nm were observed in the XL spectra and are attributed to Cl excitons, V(k)(Cl2-), the 4f65d1 (2e(g)) --> 4f7 (8S(7/2)) transition of Eu2+, and oxygen vacancies, respectively. Three emission peaks at 315, 365, and 390 nm were observed in the PL and TL measurements. These three emissions are from the transitions of 4f7(6I(7/2)) --> 4f7(8S(7/2)), 4f7(6P(7/2)) --> 4f7(8S(7/2)), and 4f65d1 (2e(g)) --> 4f7(8S(7/2)) of Eu2+, respectively. In our measurements, we observed that the emission of Eu2+ increases in intensity upon beta-irradiation and did not see any signals related to Eu3+ ions, which indicates that Eu2+ ions might not be oxidized to Eu3+ upon X-ray or beta-irradiation. Instead, the color centers, Cl excitons, and oxygen defects are created and are stable at room temperature, and they might play a key role in the storage luminescence.