Modeling and optimization of Au-GaAs plasmonic nanoslit array structures for enhanced near-infrared photodetector applications
Modeling and optimization of Au-GaAs plasmonic nanoslit array structures for enhanced near-infrared photodetector applications
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DOI：
10.1117/1.jnp.11.016017
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发表时间：
2017-01-01
影响因子：
1.5
通讯作者：
Herzog, Joseph B.
中科院分区：
文献类型：
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作者：
Brawley, Zachary T.;Bauman, Stephen J.;Herzog, Joseph B.
这项理论工作探讨了各种几何形状的Au等离子体纳米缝阵列结构如何提高GaAs光电探测器的总光学增强。计算模型研究了这些特征。改变电极间距、宽度和厚度会显著影响GaAs中的增强。增强峰随着Au宽度和厚度的增加而衰减。这些峰与入射的近红外波长共振。发现增强值随着电极间距的减小而增加。另外，对在Au和GaAs之间包含Ti的模型进行计算，以模拟必要的粘附层。结果表明，随着Ti层厚度的增加，GaAs中的光增强效应减小. Au电极的最佳尺寸包括240 nm的宽度、60 nm的厚度、5 nm的电极间距和最小Ti厚度。优化设计已被证明可以提高增强值，其比非优化几何形状大25倍，比具有大电极间距的结构大300倍。还发现，在阵列中的金属的宽度起着更重要的作用，在影响场增强比阵列的周期。(C)作者。由SPIE在知识共享署名3.0未移植许可下发布。分发或复制本作品的全部或部分要求完全归属于原始出版物，包括其DOI。
This theoretical work explores how various geometries of Au plasmonic nanoslit array structures improve the total optical enhancement in GaAs photodetectors. Computational models studied these characteristics. Varying the electrode spacing, width, and thickness drastically affected the enhancement in the GaAs. Peaks in enhancement decayed as Au widths and thicknesses increased. These peaks are resonant with the incident near-infrared wavelength. The enhancement values were found to increase with decreasing electrode spacing. Additionally, a calculation was conducted for a model containing Ti between the Au and the GaAs to simulate the necessary adhesion layer. It was found that optical enhancement in the GaAs decreases for increasing Ti layer thickness. Optimal dimensions for the Au electrode include a width of 240 nm, thickness of 60 nm, electrode spacing of 5 nm, and a minimum Ti thickness. Optimal design has been shown to improve enhancement to values that are up to 25 times larger than for nonoptimized geometries and up to 300 times over structures with large electrode spacing. It was also found that the width of the metal in the array plays a more significant role in affecting the field enhancement than does the period of the array. (C) The Authors. Published by SPIE under a Creative Commons Attribution 3.0 Unported License. Distribution or reproduction of this work in whole or in part requires full attribution of the original publication, including its DOI.