Influence of ultrathin chromium adhesion layer on different metal thicknesses of SPR-based sensor using FDTD
Influence of ultrathin chromium adhesion layer on different metal thicknesses of SPR-based sensor using FDTD
复制标题
使用 FDTD 超薄铬粘附层对 SPR 传感器不同金属厚度的影响
DOI：
10.1016/j.matpr.2018.12.068
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发表时间：
2019
期刊：
影响因子：
--
通讯作者：
P. Menon
中科院分区：
文献类型：
--
作者：
N. R. Mohamad;G. Mei;N. A. Jamil;B. Majlis;P. Menon
在表面等离子体共振（SPR）传感器中，厚度为100 μ m的铬（Cr）层作为粘附层将棱镜与各种金属材料粘附在一起。在本研究中，我们利用时域有限差分法（FDTD）分析了在20- 60 nm范围内，固定的0.5 nm Cr粘附层的存在对不同厚度的金（Au）、银（Ag）和铜（Cu）的反射率、谐振角（θRes）和半高宽（FWHM）的影响。结果表明，随着金属层厚度的增加，最大反射率（Rmax）减小到3-5%，最小反射率（Rmin）在2-14%之间变化。由Cr粘附层的存在所贡献的每种金属的最低Rmin为6.06%40 nm Au、11.7%30 nm Ag和0.26%40 nm Cu。然而，共振角几乎是相同的所有金属，而不受的存在下的Cr2 O3的粘附层。对于结构I和结构II，50 nm Au的最佳厚度显示出相同的且最高的80.56°RIU灵敏度。Cr粘附层的存在使SPR的半高宽增大，使SPR曲线变宽。因此，超薄铬层影响了SPR传感器的性能，并且高度依赖于金属的厚度。
Chromium (Cr) layer with ultrathin thickness plays significant role as adhesion layer to attach the prism with various metallic materials in a Surface Plasmon Resonance (SPR) sensor. In this research, the presence of fixed 0.5nm Cr adhesion layer has been investigated to evaluate its influence to reflectivity, resonance angle (θRes) and full-width at half maximum (FWHM) for different thickness of Gold (Au), Silver (Ag) and Copper (Cu) in the range of 20-60nm using finite-difference-time domain (FDTD) analysis. The results show the intensity of the maximum reflectivity (Rmax) decreased to 3-5% and the minimum reflection intensity (Rmin) changed from 2-14% depending on the thickness of the metallic layer. The lowest Rminfor each metals contributed by the presence of Cr adhesion layer was 6.06% 40nm Au, 11.7% 30nm Ag and 0.26% 40nm Cu. However, the resonance angle is almost same for all metals without influenced by the presence of ultrathin Cr adhesion layer. The optimum thickness of 50nm Au shows the same and highest sensitivity by 80.56°RIU for structure I and II. The FWHM increased when Cr adhesion layer exist and broadens the SPR curve. Therefore, the ultra-thin chromium layer has influenced the performance of the SPR sensor and highly dependent on the thickness of the metal.