表面等离子共振氢敏传感器理论和模拟

提出了一种钯(Pd)膜氢敏感表面等离子共振传感器结构,该传感器以镀在棱镜端面的 Pd作为氢敏感膜。Pd 膜吸氢以后发生化学反应,生成的 PdHx使折射率发生变化,同时,它作为金属膜产生 SPW,当折射率变化时又在金属和介质表面产生表面等离子共振。利用 Fortran 语言程序进行了表面等离子共振氢敏传感器的 Pd 膜厚度和传感器灵敏度数值模拟。氢气浓度的变化引起折射率的变化,数值模拟表明,表面等离子共振氢敏传感器的灵敏度与 Pd 膜厚度有关,当 Pd膜的厚度在 10-30nm 时,氢气浓度在 1%-10%范围内具有较高的灵敏度。这种传感器结构将用于监测氢气作燃料的商用和军用机车的氢气泄漏。

Theory and simulation of surface plasma resonance hydrogen sensor

A Surface Plasma Resonance (SPR) hydrogen sensor coated with Pd film on its prism side as hydrogen-sensitive film is proposed. When hydrogen gas is absorbed into the Pd thin layer, a process of chemical reaction occurs and then a Pd hydride (PdHx) is formed, which will change the refraction index with the increase or decrease of gas concentration. At the same time, a SPR occurs because of the excitation of Surface Plasma Wave (SPW) supported by thin metal layer. The numerical simulations for Pd film thickness and sensitivity of the hydrogen sensing system are carried out by Fortran program. The simulation results show that the sensitivity of the surface plasma resonance hydrogen sensor is related to Pd film thickness. When the thickness of Pd film is within the range of 10-30nm and the hydrogen concentration is within the range of 1%-10%, the system has a high sensitivity. This sensor structure can be applied to detecting hydrogen leakage of commercial and military vehicles with hydrogen as fuel.