Oxidation pathway to the titanium dioxide metasurface for harnessing photoluminescence
Oxidation pathway to the titanium dioxide metasurface for harnessing photoluminescence
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DOI：
10.1063/5.0046637
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发表时间：
2021-04
影响因子：
3.2
通讯作者：
S. Murai;Feifei Zhang;Koki Aichi;Katsuhisa Tanaka
中科院分区：
文献类型：
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作者：
S. Murai;Feifei Zhang;Koki Aichi;Katsuhisa Tanaka
尽管二氧化钛(TiO2)是一种很有前途的可见光亚表面成分，但由于其内在的化学/物理稳定性，很难加工成高精度的纳米结构，实验演示受到了限制。本文提出了一种利用传统提拉法制备的钛纳米颗粒阵列氧化制备二氧化钛亚表面的简便方法。在优化的空气中热处理工艺下，钛纳米粒子转变为纳米二氧化钛粒子，其尺寸膨胀由钛和二氧化钛之间的摩尔体积失配来预测，同时保持了整体的周期性排列。我们将这一技术应用于在掺Ce3+的Y3+石榴石(YAG：Ce)荧光板上制备的钛纳米颗粒阵列，并证明了发射通过准表面的定向输出耦合。在正向方向上，YAG：Ce平板的光致发光得到了增强，是不带中间表面的平面型的3倍。由于二氧化钛在可见光下的高透明度和无损特性，目前的亚表面并不降低由YAG：Ce板和二氧化钛亚表面组成的系统的总量子产率，这有利于固体照明的应用。
Although titanium dioxide ( TiO 2) is a promising constituent of the metasurface operative in the visible, the experimental demonstration is limited so far because TiO 2 is intrinsically chemically/physically stable and is hard to be processed into nanostructures with high precision. In this paper, we develop a facile pathway to fabricate the TiO 2 metasurface via oxidation of Ti nanoparticle array that can be made by the conventional lift-off process. Under an optimized heat-treatment procedure in air, Ti nanoparticles are converted to TiO 2 nanoparticles with a size expansion predictable by the molar volume mismatch between Ti and TiO 2, while the global periodic arrangement is retained. We apply this technique to a Ti nanoparticle array fabricated on the phosphor plate of yttrium aluminum garnet doped with Ce 3 + (YAG:Ce) and demonstrate the directional outcoupling of emission through the metasurface. The photoluminescence from the YAG:Ce plate is directionally enhanced in the forward direction, as large as three times as much compared to that from the flat YAG:Ce plate without the metasurface. Because of the high transparency and lossless feature of TiO 2 in the visible, the present metasurface does not lower the total quantum yield of the system consisting of the YAG:Ce plate and the TiO 2 metasurface, which is beneficial for the solid-state-lighting application.