Tunable emission color of Li2SrSiO4:Tb3+ due to cross‐relaxation process and optical thermometry investigation
Tunable emission color of Li2SrSiO4:Tb3+ due to cross‐relaxation process and optical thermometry investigation
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DOI：
10.1111/jace.15481
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发表时间：
2018-07
影响因子：
3.9
通讯作者：
Xiao Zhou;Sha Jiang;Guotao Xiang;Xiaojia Tang;Xiaobing Luo;Li Li-Li;Xianju Zhou
中科院分区：
文献类型：
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作者：
Xiao Zhou;Sha Jiang;Guotao Xiang;Xiaojia Tang;Xiaobing Luo;Li Li-Li;Xianju Zhou
采用固相反应法制备了Li2SrSiO4：xTb3+(0.2%、0.4%、0.6%、0.8%、2%、4%和6%)系列荧光粉。研究发现，这种硅酸盐荧光粉由于Tb3+离子的自旋允许4f8→4f75d1跃迁，在近紫外区(230-300nm处)有一个较宽的激发带，其确切位置取决于晶格的晶场。5D3→5D4和7F6→7F0产生的交叉弛豫过程发生在不同的Tb3+离子之间。仅通过控制Tb3+的浓度，就可以使Li2SrSiO4：xTb3+的发光颜色由蓝变绿。此外，还详细讨论了浓度猝灭机制、能量迁移类型、交叉驰豫速率和效率。最后，通过随温度变化的发射光谱研究了薄膜的光学测温性质。结果表明，低浓度掺杂样品(Li2SrSiO4：0.4%Tb3+)在发光强度比(FIR)方面表现出显著的光学测温特性，而高浓度掺杂样品(Li2SrSiO4：4%Tb3+)的发光强度损失较小。这说明掺Tb硅酸盐荧光粉是一种多功能材料，在显示领域和光学测温方面具有潜在的应用前景。
A series of Li2SrSiO4:xTb3+(0.2%, 0.4%, 0.6%, 0.8%, 2%, 4%, and 6%) phosphors were prepared by conventional solid‐state reaction. It was found that this silicate phosphor has a wide excitation band at near‐ultraviolet region (230‐300 nm) due to spin‐allowed4f8→4f75d1transitions of Tb3+ions, with the exact position dependent on the crystal field of the lattice. The cross‐relaxation process originating from5D3→5D4and7F6→7F0happened between different Tb3+ions. It leads to the luminescence color of Li2SrSiO4: xTb3+tuning from blue to green just by controlling Tb3+concentrations. Furthermore, concentration quenching mechanism, energy migration type, cross‐relaxation rate and efficiency, are discussed in detail. Finally, optical thermometry properties were investigated via temperature‐dependent emission spectra. The results show that low‐concentration‐doped sample (Li2SrSiO4:0.4%Tb3+) shows remarkable optical thermometry based on fluorescence intensity ratio (FIR) between the blue and green emission of Tb3+ions, whereas the high‐concentration‐doped sample (Li2SrSiO4:4%Tb3+) demonstrates small emission intensity loss. It illustrates that terbium‐doped silicate phosphor is a multifunctional material with potential application for display field and optical thermometry.