Exploiting plasmons in 2D metals for refractive index sensing: Simulation study
Exploiting plasmons in 2D metals for refractive index sensing: Simulation study
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DOI：
10.1063/5.0123648
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发表时间：
2022-12
影响因子：
3.2
通讯作者：
L. Kang;J. Robinson;D. Werner
中科院分区：
文献类型：
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作者：
L. Kang;J. Robinson;D. Werner
超薄和二维（2D）金属可以支持强等离子体激元，伴随着紧场约束和大的场增强。因此，表现出等离子体共振的2D金属纳米结构对环境高度敏感，并且本质上适合于光学感测。在这里，基于概念验证的数值研究，支持红外等离子体激元的纳米工程的2D-金属薄膜被证明能够实现高度响应的折射率（RI）传感。对于在约1600 nm的波长处表现出等离子体共振的3 nm-Au纳米带，对于100 nm厚的分析物层观察到每折射率单位（RIU）SRI> 650 nm的RI灵敏度。二维金系统的参数研究表明，2D金属厚度的RI灵敏度的强烈依赖。此外，对于薄至1 nm的分析物层，在原子级薄的2D-In（2D-Ga）纳米带中观察到高达110（90 nm/RIU）的RI灵敏度，所述纳米带在中红外波长处表现出高度局部化的等离子体共振。我们的研究结果不仅揭示了2D-金属系统的非凡传感特性，而且还为基于2D-金属的等离子体器件的发展提供了洞察力，以增强IR检测。
Ultrathin and two-dimensional (2D) metals can support strong plasmons, with concomitant tight field confinement and large field enhancement. Accordingly, 2D-metal nanostructures exhibiting plasmonic resonances are highly sensitive to the environment and intrinsically suitable for optical sensing. Here, based on a proof-of-concept numerical study, nano-engineered ultrathin 2D-metal films that support infrared plasmons are demonstrated to enable highly responsive refractive index (RI) sensing. For 3 nm-Au nanoribbons exhibiting plasmonic resonances at wavelengths around 1600 nm, a RI sensitivity of SRI > 650 nm per refractive index unit (RIU) is observed for a 100 nm-thick analyte layer. A parametric study of the 2D-Au system indicates the strong dependence of the RI sensitivity on the 2D-metal thickness. Furthermore, for an analyte layer as thin as 1 nm, a RI sensitivity up to 110 (90 nm/RIU) is observed in atomically thin 2D-In (2D-Ga) nanoribbons exhibiting highly localized plasmonic resonances at mid-infrared wavelengths. Our results not only reveal the extraordinary sensing characteristics of 2D-metal systems but also provide insight into the development of 2D-metal-based plasmonic devices for enhanced IR detection.