Ca8MgSm1-x(PO4)7:xEu3+, promising red phosphors for WLED application
Ca8MgSm1-x(PO4)7:xEu3+, promising red phosphors for WLED application
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DOI：
10.1016/j.jallcom.2018.10.317
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发表时间：
2019-03-05
影响因子：
6.2
通讯作者：
Burns, Peter C.
中科院分区：
文献类型：
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作者：
Deyneko, Dina, V;Nikiforov, Ivan, V;Burns, Peter C.
采用高温固相反应法在空气中合成了具有白锁石型结构的新型红色发光材料Ca8MgSm1-x(PO4)(7)：xEu(3+)。用粉末X射线衍射仪、光致发光谱和荧光衰减法对其结构和发光性能进行了表征。所有样品都具有预期的菱面体结构，其中R(3)位于Barc空间基团上。非极性空间群的光致发光研究也证实了这一点。这个空间群允许Eu3+的禁忌跃迁。D-5(0)-F-7(0)中只有一个Shtark组分的存在证实了只存在一个含有Eu3+离子的非等效位。高强度的跃迁比D-5(0)-F-7(2)/D-5(0)-F-7(1)建立了Eu3+离子的强烈无序环境。因此，基质中的M1-M3位被Ca~(2+)、Sm~(3+)和Eu~(3+)占据，而M5则完全被Mg~(2+)占据。Ca8MgSm1-x(PO4)(7)：XEu3+的最佳掺杂浓度为x=0.75。由于Eu3+的高强度发光，Sm3+的发光被抑制，但Sm3+的贡献体现在CIE坐标的能量转移过程和位移上。此外，合成的Ca8MgSm0.25(PO4)(7)：0.75Eu(3+)(x=0.650；y=0.345)的色度坐标接近标准红光发射点(x=0.67，y=0.33)。实验数据表明，Ca8MgSm1-x(PO4)(7)：XEu3+在近紫外光激发下是一种很有前途的白光二极管红色荧光粉。(C)2018爱思唯尔B.V.保留所有权利。
Novel red emitting phosphors Ca8MgSm1-x(PO4)(7):xEu(3+) with whitlockite-type structure were prepared by a high temperature solid-state reaction in air. Powder X-ray diffraction (PXRD), photoluminescence spectra, and fluorescence decay were used to characterize the structure and luminescence properties. All samples were found to have the expected rhombohedral structure with R (3) over barc space group. The non-polar space group is also confirmed by a photoluminescence study. This space group allows forbidden transitions for Eu3+. The presence of only one Shtark component in D-5(0)-F-7(0) confirms the presence of only one non-equivalent site containing Eu3+ ions. The high intensity of the transition ratio D-5(0)-F-7(2)/D-5(0)-F-7(1) establishes the strongly disordered environment of the Eu3+ ions. Thus, M1-M3 sites in the host matrix are occupied by Ca2+, Sm3+, and Eu3+ ions, whereas M5 is fully occupied by Mg2+. The optimal concentration was found with x = 0.75 in Ca8MgSm1-x(PO4)(7):XEu3+ phosphors. The emitting of Sm3+ was depressed due to the high intensity of Eu3+ luminescence; however, the contribution of Sm3+ is manifested in the energy transfer process and shift of CIE coordinates. Furthermore, the CIE chromaticity coordinate of as-prepared Ca8MgSm0.25(PO4)(7):0.75Eu(3+) (x = 0.650; y = 0.345) is close to the standard red-emitting point (x = 0.67, y=0.33). The experimental data indicate that Ca8MgSm1-x(PO4)(7):XEu3+ upon excitation by near-UV radiation is a promising red phosphor for white-light-emitting diodes. (C) 2018 Elsevier B.V. All rights reserved.