Centre for Micro-Photonics, Faculty of Science, Engineering and Technology , Swinburne University of Technology , Hawthorn , VIC 3122 , Australia.
Center for Physical Sciences and Technology , A. Goštauto 9 , LT-01108 Vilnius , Lithuania.
ACS Sens. 2019 Sep 27;4(9):2389-2394. doi: 10.1021/acssensors.9b00980. Epub 2019 Aug 23.
A hydrogen sensor based on plasmonic metasurfaces is demonstrated to exhibit the industry-required 10 s reaction time and sensitivity. It consists of a layer of either Y or WO sandwiched between a top Pd nanodisk and a Au mirror at the base. The phase change layer (Y, WO) reacts with hydrogen, and the corresponding change of the refractive index (permittivity) is detected by the spectral shift of the resonance dip in reflectance at the IR spectral window. This direct reflectance readout of the permittivity change due to hydrogen uptake is fast and is facilitated by radiation field enhancement extending into the phase change volume. Numerical modeling was used to elucidate the effects that real and imaginary parts of the refractive index exert on the spectral shifts of resonance. The mechanism of sensor performance is outlined, and a possibility to tune its spectral range of operation by the diameter of the Pd nanodisk and thickness of the phase change material makes this design applicable to other molecular detection applications including surface-enhanced IR absorption.
一种基于等离子体超表面的氢气传感器被证明具有工业所需的 10 s 响应时间和灵敏度。它由一层 Y 或 WO 夹在顶部的 Pd 纳米盘和底部的 Au 镜之间组成。相变层（Y、WO）与氢气反应，通过在红外光谱窗口的反射率共振峰的光谱位移来检测相应的折射率（介电常数）变化。由于氢的吸收导致的介电常数变化的这种直接反射读出速度很快，并且由于辐射场增强延伸到相变体积中而得到促进。数值模拟用于阐明折射率的实部和虚部对共振光谱位移的影响。概述了传感器性能的机制，并通过 Pd 纳米盘的直径和相变材料的厚度来调整其光谱工作范围的可能性，使得这种设计适用于其他分子检测应用，包括表面增强红外吸收。
