Improved thermal stability of luminescence by anion modification in Na2Y(MoO4)(PO4):Tb3+,Eu3+ red-emitting phosphors
Improved thermal stability of luminescence by anion modification in Na2Y(MoO4)(PO4):Tb3+,Eu3+ red-emitting phosphors
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DOI：
10.1016/j.jallcom.2020.155438
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发表时间：
2020-10
影响因子：
6.2
通讯作者：
Zhenbin Guo;Bojana Milicevic;Jiajun Feng;Lei Zhou;Fen Yao;Senchuan Huang;Zhan-chao Wu;W. Khan-
中科院分区：
文献类型：
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作者：
Zhenbin Guo;Bojana Milicevic;Jiajun Feng;Lei Zhou;Fen Yao;Senchuan Huang;Zhan-chao Wu;W. Khan-
多面体阴离子被用作支持主体结构以改善磷光体的发光性能。然而，通过阴离子修饰提高发光热稳定性的潜在机制却很少被研究。本文首次报道了Na_（2-n）Y（MoO_4）_（1+n）（PO_4）_（1-n）：Tb ~（3+），Eu ~（3+）红色荧光粉的热猝灭和发光性能可以通过酸自由基的比例来调节。Rietveld精修和德拜温度计算表明，[PO 4]3-对[MoO 4]2-的微量取代导致了基质晶格的收缩和晶格刚性的提高，但并不改变基质的晶型。通过变温X射线衍射、拉曼光谱、形成能和功函数对发光的热稳定性进行了详细的解释。阴离子改性策略为提高荧光粉的热稳定性和调节荧光光谱提供了一种有效的方法，也为新型荧光粉的开发提供了参考。此外，Na1.4Tb0.5（MoO 4）1.6（PO 4）0.4：0.5Eu3+红色荧光粉的内量子效率为66.67%，在425 K下的积分发光强度是300 K下的86.4%。这种可控制的局部结构依赖的发光使得这种新型的红色荧光粉对于基于蓝光和近紫外芯片的WLED都具有吸引力。
Polyhedral anions have been used as supporting host structure to improve the luminescent properties of phosphors. However, the underlying mechanism for improving the thermal stability of luminescence by anion modification is rarely studied. In this paper, it was reported for the first time that thermal quenching and luminescent properties of red-emitting phosphors, Na2-nY(MoO4)1+n(PO4)1-n:Tb3+,Eu3+, can be adjusted by the ratio of acid radicals. Rietveld refinements and Debye temperature calculations show that the subtle replacement of [MoO4]2–by [PO4]3–results in the shrinkage of the crystal lattice and an improvement in lattice rigidity of the host, but does not change the crystal type. A detailed explanation of the mechanism for adjustable thermal stability of luminescence is providedviatemperature-dependent X-ray diffraction, Raman, formation energy, and work function. The strategy of anion modification reveals an effective method for improving the thermal stability and tuning the luminescent spectra of phosphors, it also sheds light on the development of new phosphors. Furthermore, Na1.4Tb0.5(MoO4)1.6(PO4)0.4:0.5Eu3+red-emitting phosphor with an internal quantum efficiency of 66.67% can be efficiently excited with blue light (465 nm) and the integrated intensity at 425 K is 86.4% of that at 300 K. The controllable local structure-dependent luminescence makes this novel red-emitting phosphor attractive for both blue and near-UV chips based WLEDs.