Controllable and tuneable growth of NaYbF 4 :Tm(0.5%)Fe(5%)@Na(Yb/Y)F 4 -core@shell structures and the effect of their geometry on upconversion luminescence
Controllable and tuneable growth of NaYbF 4 :Tm(0.5%)Fe(5%)@Na(Yb/Y)F 4 -core@shell structures and the effect of their geometry on upconversion luminescence
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可控%20and%20可调%20增长%20of%20NaYbF%204%20:Tm(0.5%)Fe(5%)@Na(Yb/Y)F%204%20-核@壳%20结构%20and%20%20效果
DOI：
10.1039/d3tc01215h
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发表时间：
2023
影响因子：
6.4
通讯作者：
Ureña-Horno E
中科院分区：
文献类型：
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作者：
Ureña-Horno E
稀土掺杂上转换纳米材料(UCNPs)是一类具有优异发光性能的纳米材料。然而，由于其相对较低的上转换量子产率，UCNP的实际应用一直受到阻碍。提高它们的效率，从而提高它们的亮度，是这些新兴材料的一个关键目标。本研究以NaYbF4：Tm(0.5%)Fe(5%)为核心模板，合成了一系列新型的核壳结构，以调节Na(Yb/Y)F4的壳层生长。在这里，我们观察到，通过控制壳层材料中Y3+/Yb3+离子的比例，可以微调UCNP的尺寸和形貌，从而产生当Y3+浓度较高时形成的小棒状结构，以及当Yb3+浓度较高时形成的较大的六方板状结构。在光学性质方面，测量了纯核壳结构和核壳结构的UC发光和寿命。总体而言，UCNP的发射强度和寿命随着纳米颗粒尺寸的增大而增加。我们观察到，在相同的实验条件下，具有六角形的较大的核@壳纳米结构比具有小的纳米棒形状的和仅具有核的纳米结构具有更明亮的UC发射。基于我们的发现，我们提出了通过改变壳层材料中Y3+/Yb3+离子浓度比对纳米结构的几何变化而产生的各种能量传递途径。我们的结果对于理解UCNP的几何结构与其UC光学性质之间的关系具有重要的意义。
Lanthanide doped upconversion nanoparticles (UCNPs) are a class of nanomaterials with excellent luminescence properties. The practical use of UCNPs, however, has been hindered by their relatively low upconversion (UC) quantum yields. Enhancing their efficiency, and therefore their brightness, is a critical goal for these emerging materials. In this study, a range of novel core@shell structures were synthesized using NaYbF4:Tm(0.5%)Fe(5%) as the core template to regulate the shell growth of Na(Yb/Y)F4. Here, we observed that the size and the morphology of the UCNPs can be fine-tuned by controlling the ratio of the Y3+/Yb3+ ions within the shell material, resulting in small rod-like structures that form when using a high concentration of Y3+ and larger hexagonal plate-like structures when using a high concentration of Yb3+. In terms of the optical properties, the UC luminescence and lifetime of the core-only and core@shell structures were measured. Overall, the emission intensity and lifetime of the UCNPs increased with the nanoparticle size. We observed that, under the same experimental conditions, larger core@shell nanostructures with a hexagonal shape showed brighter UC emission, compared to those with a small nanorod shape and core-only. Based on our findings, we propose a variety of energy transfer pathways arise through geometric alteration of the nanostructures upon varying the Y3+/Yb3+ ion concentration ratios within the shell material. Our results could have important significance for understanding the relationship between the geometry of UCNPs and their UC optical properties.