Wide tuning of the optical and structural properties of alternative plasmonic materials
Wide tuning of the optical and structural properties of alternative plasmonic materials
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DOI：
10.1364/ome.5.002415
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发表时间：
2015-11-01
影响因子：
2.8
通讯作者：
Dal Negro, Luca
中科院分区：
文献类型：
--
作者：
Wang, Yu;Capretti, Antonio;Dal Negro, Luca
替代的等离子体材料由于其与常规金属相比的优点而引起了相当大的关注，包括与Si加工的兼容性、光学性质的可调谐性和降低的损耗。在这项工作中，我们表明，通过磁控溅射制造的材料的沉积后退火允许大的调整的结构和光学色散特性的氧化铟锡（ITO），铝掺杂的氧化锌（AZO）和氮化钛（TiN）纳米层。通过测量它们的光学带隙，我们表明，热退火处理可以显着调制这些材料中的载流子浓度，从而提供光学损耗的可调谐性，并使工程的ε近零（ENZ）制度。此外，我们进行X射线衍射（XRD）测量表明，热退火也可以有效地调整材料的晶粒尺寸。最后，还研究了不同退火气体对自由载流子浓度的影响。我们在这项工作中展示的光学和结构特性的宽调谐性和控制对于在宽频谱上设计共振光学响应对于等离子体、超材料和变换光学器件的应用是重要的。(C)2015美国光学学会
Alternative plasmonic materials have attracted considerable attention due to their advantages compared to conventional metals, including compatibility with Si processing, tunability of optical properties, and reduced losses. In this work, we demonstrate that post-deposition annealing of materials fabricated by magnetron sputtering allows large tuning of the structural and the optical dispersion properties of Indium Tin Oxide (ITO), Al-doped ZnO (AZO) and Titanium Nitride (TiN) nanolayers. By measuring their optical bandgaps, we show that thermal annealing treatments can dramatically modulate the carrier concentration in these materials, thus providing tunability of the optical losses and enabling the engineering of Epsilon-Near-Zero (ENZ) regime. Besides, we perform X-ray diffraction (XRD) measurements to show that thermal annealing can also effectively tune the materials grain sizes. Eventually, the effect of different annealing gases on the free carrier concentration has also been investigated. The wide tunability and control of the optical and structural properties that we demonstrated in this work is important to engineer resonant optical responses across a wide frequency spectrum for device applications to plasmonics, metamaterials and transformation-optics. (C) 2015 Optical Society of America