Dopant Site Environment and Spectrum Blue Shift of Yellow-Emitting Solid Solution Phosphor Ba2-xSrxMg(PO4)2:Eu2+
Dopant Site Environment and Spectrum Blue Shift of Yellow-Emitting Solid Solution Phosphor Ba2-xSrxMg(PO4)2:Eu2+
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黄光固溶体Ba2-xSrxMg(PO4)(2):Eu2的掺杂位点环境与光谱蓝移
DOI：
10.1111/jace.13969
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发表时间：
2016-02-01
影响因子：
3.9
通讯作者：
Ning, Lixin
中科院分区：
文献类型：
--
作者：
Hu, Qingsong;Pan, Zaifa;Ning, Lixin
在Ba_2 Mg（PO_4）（2）：Eu ~（2+）（x=0 ~ 1.5）固溶体中，当Sr ~（2+）取代Ba_2 Mg（PO_4）（2）晶格中的大离子Ba ~（2+）时，观察到了未预料到的黄光发射光谱蓝移。采用固相反应法制备了固溶体荧光粉，以澄清激活剂Eu 2+的局域位环境，并对反常的长波长黄光发射进行调谐。经Rietveld精修，BaSrMg（PO 4）（2）相与Ba 2 Mg（PO 4）（2）相是同构的。密度泛函理论计算和光致发光研究表明，BaSrMg（PO 4）（2）中激活离子Eu 2+以等概率占据Sr 2+和Ba 2+位置，并产生异常的黄光发射。随着Sr ~（2+）取代浓度x从0.1增加到1，Ba ~（2-x）Sr ~ xMg（PO_4）（2）：Eu ~（2+）的黄光发射逐渐蓝移。这种不寻常的蓝移解释的基础上的晶体结构参数的演变，由于Sr 2+取代，随后，提出了一个网站的环境膨胀机制。该机理可作为一个通用模型，揭示阳离子取代引起的光谱移动的潜在因素，并有助于设计新的固溶体荧光粉。
An unexpected spectrum blue shift of the yellow emission was observed for solid solution phosphors Ba2-xSrxMg(PO4)(2):Eu2+ (x=0-1.5), when bigger ions Ba2+ were substituted by smaller ions Sr2+ in Ba2Mg(PO4)(2) lattices. The solid solution phosphors were prepared by a solid-state reaction to clarify the local sites environment of activators Eu2+ and tune the anomalous long-wavelength yellow emission. BaSrMg(PO4)(2) phase was identified to be isostructural with Ba2Mg(PO4)(2) by Rietveld refinements. DFT calculation and photoluminescence show that the activator ions Eu2+ in BaSrMg(PO4)(2) occupy Sr2+ and Ba2+ sites at an equal probability and both generate an anomalous yellow emission. The yellow emission from Ba2-xSrxMg(PO4)(2):Eu2+ was gradually blue shift with increasing Sr2+ substitution concentration x from 0.1 to 1. Such unusual blue shift is interpreted based on the evolution of crystal structure parameters due to Sr2+ substitution, and subsequently, a site environmental expansion mechanism is proposed. The proposed mechanism could serve as a general model to reveal the underlying factors for spectrum shift caused by cation substitution and contribute to design new solid solution phosphors.