Disorder-Induced Broadband Near-Infrared Persistent and Photostimulated Luminescence in Mg2SnO4:Cr3.
Disorder-Induced Broadband Near-Infrared Persistent and Photostimulated Luminescence in Mg2SnO4:Cr3.
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DOI：
10.1021/acs.inorgchem.0c02941
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发表时间：
2021-01
影响因子：
4.6
通讯作者：
W. Xie;Wei Jiang;Rongfu Zhou;Junhao Li;Jianhong Ding;Haiyong Ni;Qiuhong Zhang;Q. Tang;J. Meng;Litian Lin
中科院分区：
文献类型：
--
作者：
W. Xie;Wei Jiang;Rongfu Zhou;Junhao Li;Jianhong Ding;Haiyong Ni;Qiuhong Zhang;Q. Tang;J. Meng;Litian Lin
具有近红外（NIR）持续发光（PersL）和近红外-近红外光激发发光（PSL）特性的材料是光子能量收集和释放的有吸引力的平台。在这项工作中，我们开发了Mg2SnO4:Cr作为宽带近红外PersL和NIR-to-NIR PSL材料（发光最大值在~ 800 nm），并揭示了PersL和PSL特性的起源。根据Rietveld细化，该材料具有逆尖晶石结构，在Wyckoff 16d位点具有Mg2+和Sn4+无序。Cr k边x射线吸收近边结构（XANES）光谱显示，掺杂的Cr离子具有+3价态，并以八面体配位占据无序（Mg,Sn）位。无序导致Cr3+中心出现多个，宽带发光源于Cr3+在晶体场强中等位置的4T2（4F）→4A2跃迁。利用初始上升法对热释光（TL）光谱进行分析，发现陷阱深度的分布是连续的，这与Mg2+和Sn4+在Cr3+中心的第二配位球上的随机分布有关，而与氧相关缺陷无关。用近红外激光刺激材料，由于PSL工艺，近红外PersL得到显著增强。宽带PersL和PSL在100 h后可检测到，并且具有良好的组织穿透性，因此开发的Mg2SnO4:Cr3+在光学信息存储/读取和无自荧光生物成像方面具有潜在的应用前景。最后，提出了三个晶体和电子结构因素筛选新的Cr3+活化的PersL和PSL材料。
Materials with near-infrared (NIR) persistent luminescence (PersL) and NIR-to-NIR photostimulated luminescence (PSL) properties are attractive platforms for photonic energy harvesting and release. In this work, we develop Mg2SnO4:Cr as a broadband NIR PersL and NIR-to-NIR PSL material (luminescence maxima at ∼800 nm) and reveal the origin of the PersL and PSL properties. The material has an inverse spinel structure with the Mg2+ and Sn4+ disorder at the Wyckoff 16d site based on the Rietveld refinement. Cr K-edge X-ray absorption near-edge structure (XANES) spectra uncover that the doped Cr ions have a +3 valence state and occupy the disordered (Mg,Sn) site with octahedral coordination. The disorder results in multiple Cr3+ centers, and the broadband luminescence originates from the 4T2(4F) → 4A2 transition of Cr3+ at sites with intermediate crystal field strength. The distribution of trap depths is continuous according to the analysis of thermoluminescence (TL) spectra using the initial rising method, which relates to the random distribution of Mg2+ and Sn4+ at the second coordination sphere of the Cr3+ centers rather than the oxygen-related defects. Stimulating the material with a NIR laser, the NIR PersL gets significantly enhanced due to a PSL process. The broadband PersL and PSL are detectable beyond 100 h and have good tissue penetrability and therefore the developed Mg2SnO4:Cr3+ has potential in applications of optical information storage/reading and autofluorescence-free bioimaging. Finally, three crystal and electronic structure factors are proposed for screening new Cr3+-activated PersL and PSL materials.