Optimizing Gas Sensor Performance Using Bilayer Surface Plasmon System

TL;DR

This study enhances gas sensor performance by optimizing bilayer surface plasmon systems, demonstrating improved sensitivity over single-layer sensors through both theoretical calculations and experimental validation.

Contribution

It introduces optimized gold-silver bilayer configurations for gas sensing, highlighting the impact of layer arrangement and thickness on sensitivity improvements.

Findings

Gold on silver bilayer achieves highest sensitivity at ~55 nm thickness.

Silver on gold configuration is sensitive but prone to corrosion.

Bilayer systems outperform single gold thin films in gas detection.

Abstract

The sensitivity of a gold-silver bilayer system for gas detection was investigated using angle-fixed reflectance measurements and numerical calculations based on the transfer-matrix method. Two configurations of bilayer systems were analyzed: gold on silver and silver on gold. According to calculations, the best sensitivity values were achieved with a total thickness of approximately 55 nm for the gold on silver system and approximately 65 nm for the silver on gold system. These calculations were supported by experimental results in a Kretschmann configuration for ethanol gas sensing. The bilayer systems showed a huge advantage compared to the widely used single gold thin film, however, special attention should be paid to the silver on gold configuration, as corrosion plays an important role in decreasing sensitivity.