Optimized Titanium Nitride Epitaxial Film for Refractory Plasmonics and Solar Energy Harvesting
Optimized Titanium Nitride Epitaxial Film for Refractory Plasmonics and Solar Energy Harvesting
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DOI：
10.1021/acs.jpcc.1c03053
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发表时间：
2021-06
影响因子：
3.7
通讯作者：
Ragini Mishra;Ching-Wen Chang;A. Dubey;Zong-Yi Chiao;T. Yen;Ho Wai Howard Lee;Yu-Jung Lu;S. Gwo
中科院分区：
文献类型：
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作者：
Ragini Mishra;Ching-Wen Chang;A. Dubey;Zong-Yi Chiao;T. Yen;Ho Wai Howard Lee;Yu-Jung Lu;S. Gwo
氮化钛(TiN)是一种新兴的难熔等离子体材料，由于其在可见光和近红外区域具有优异的光学性能、较高的熔化温度、极高的机械硬度以及在恶劣环境下抗材料退化的稳定性。近年来，TiN等离激元表面被提出作为宽带光吸收体和窄带热发射体，这对高效太阳能热光伏发电具有重要意义。在这里，我们展示了一种利用氮等离子体辅助分子束外延技术在c面蓝宝石衬底上生长的抗氧化TiN外延薄膜制成的单层亚表面宽带吸收材料，在可见光谱范围内的∼吸收率为90%。与传统反应溅射方法制备的氮氧化钛(TiOxNy)薄膜相比，分子束外延生长的无氧化学计量比TiN薄膜的等离子体激元特性得到了优化。此外，分子束外延生长的TiN金属表面在850℃下进行真空退火，在130日照下进行辐照处理，证实了其良好的热稳定性和化学稳定性。
Titanium nitride (TiN) is an emerging material for refractory plasmonics owing to its excellent optical properties in the visible and near-infrared regions, high melting temperature, extreme mechanical hardness, and stability against material degradation in tough environments. Recently, TiN plasmonic metasurfaces have been proposed as optical broadband absorbers and narrow-band thermal emitters, which are critical for high-efficiency solar thermophotovoltaics. Here, we demonstrate a single-layer metasurface broadband absorber made from the oxidation-resistant TiN(111) epitaxial film grown on c-plane sapphire by nitrogen-plasma-assisted molecular beam epitaxy (MBE) with ∼90% absorptivity over the visible spectrum. This is accomplished by optimized plasmonic characteristics of the oxygen-free stoichiometric TiN film grown by MBE, in comparison with titanium oxynitride (TiOxNy) films prepared by the conventional reactive sputtering technique. In addition, the superb thermal and chemical stabilities of MBE-grown TiN metasurface are confirmed by vacuum annealing at 850 °C and irradiation under 130 suns in the ambient environment.