Local, Temperature-Dependent Trapping and Detrapping in the LiGa5O8:Cr Infrared Emitting Persistent Phosphor
Local, Temperature-Dependent Trapping and Detrapping in the LiGa5O8:Cr Infrared Emitting Persistent Phosphor
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DOI：
10.1149/2.0211801jss
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发表时间：
2018-01-01
影响因子：
2.2
通讯作者：
Poelman, Dirk
中科院分区：
文献类型：
--
作者：
De Clercq, Olivier Q.;Poelman, Dirk
LiGa_5O_8：Cr~（3+）（LGO：Cr）近红外发光材料在生物成像领域有着广阔的应用前景。为了提高LGO：Cr和其他掺铬长余辉材料的长余辉发光性能，需要更好地理解LGO：Cr的俘获和去俘获机制。在这项工作中，我们研究了余辉和热释光通过热衰减实验。结果表明，在LGO：Cr中存在较宽的陷阱分布。铬的发射光谱在余辉过程中发生变化，这表明不同的Cr离子在LGO主机中经历了不同的晶场，由于不同的缺陷配置，并且在局部发生脱陷过程。热释光和光谱衰减的测量结果表明，深阱附近的铬离子受到较小的晶场。合成过程中形成的空位最有可能导致这种效应。用Si 4+或Ge 4+共掺杂LGO显著改善了磷光体的持续发光，并增加了磷光体中的深陷阱的数量。(c)作者（S）2017由ECS发布。All rights reserved.
The near-infrared emitting persistent phosphor LiGa5O8:Cr3+ (LGO:Cr) has promising applications in bioimaging. In order to improve the persistent luminescence of LGO:Cr and other Cr-doped persistent phosphors, a better understanding of trapping and detrapping mechanisms is necessary. In this work, we study the afterglow and thermoluminescence via a thermal fading experiment. The results show that there is a broad trap distribution present in LGO:Cr. The emission spectrum of chromium changes during the afterglow, which indicates that different Cr ions experience a varying crystal field in the LGO host, due to different defect configurations, and that the detrapping process occurs locally. The results of thermoluminescence and spectral decay measurements show that chromium ions residing near deep traps are subject to a smaller crystal field. Vacancies formed during the synthesis are most probably causing this effect. Codoping LGO with Si4+ or Ge4+ significantly improves the persistent luminescence and increases the number of deep-lying traps in the phosphor. (c) The Author(s) 2017. Published by ECS. All rights reserved.