Preparation of Ca2Si5N8:Eu2+,Tm3+ phosphor by calcium hydride and its afterglow properties
Preparation of Ca2Si5N8:Eu2+,Tm3+ phosphor by calcium hydride and its afterglow properties
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DOI：
10.1117/12.840402
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发表时间：
2009-07
期刊：
影响因子：
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通讯作者：
B. Lei;K. Machida;T. Horikawa;H. Hanzawa
中科院分区：
文献类型：
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作者：
B. Lei;K. Machida;T. Horikawa;H. Hanzawa
以廉价的CaH 2为钙源，采用固相反应法制备了红橙色长余辉发光材料Ca 2Si 5 N8：Eu 2+，Tm 3+。在紫外光激发下，Ca_2Si_5N_8：Eu ~（2+），Tm ~（3+）荧光粉具有较宽的发光峰，峰值约为10 nm。600纳米。此外，在通过UV或可见光照射之后，（在250-400 nm范围内）激发3 min后，在0.5at%Eu ~（2+）和Tm ~（3+）共掺的荧光粉上观察到了基于Eu ~（2+）离子4f 65 d1 → 4f 7跃迁的同色强余辉，并且在除去激发源后的1小时以上，在黑暗中用肉眼可以清楚地看到其余辉。余辉衰减曲线包含快衰减和慢衰减分量。Mg 2+取代Ca 2+或加入过量的Ca 2+来改善基质中的缺陷环境，可以有效地改善余辉性能。
Reddish-orange emitting long-lasting phosphorescence phosphor Ca2Si5N8:Eu2+,Tm3+ has been prepared by solid-state reaction method using cheaper CaH2 as calcium source. Upon UV light excitation, Ca2Si5N8:Eu2+,Tm3+ phosphor gave a broad band emission peaking at ca. 600 nm. Furthermore, after irradiation by the UV or visible light (in the range of 250-400 nm) for 3 min, the same colored intense afterglow based on the 4f65d1→4f7 transition of Eu2+ ion was observed on the phosphor codoped with 0.5 at% of Eu2+ and Tm3+ ions, and its afterglow can be seen with the naked eye in the dark clearly for more than 1 h after removal of the excitation source. The afterglow decay curve contained fast decay and slow decay components. The substitution of Mg2+ to Ca2+ ions or addition of excessive Ca2+ ions into the phosphor matrix to modify the defect environment were effective to improve the afterglow properties.