Magnesium Oxide and Silicon-Assisted Surface Plasmon Resonance Sensor for Gas Detection: A Performance Analysis

The surface plasmon resonance (SPR) sensor with better sensitivity and gas detection capabilities is reported in this paper. It is based on a hybrid layer of silver (Ag)/magnesium oxide (MgO)/silicon (Si). For numerical analysis, the finite element technique (FEM) was employed. The attenuated total reflection (ATR) approach has been used for diagnosing various types of hazardous gas. The increase in the refractive index of various hazardous gases, ranging from 1.327 to 1.38 for four different types of gas, caused the resonance angle to shift. The obtained sensitivities were 86.12 deg/RIU, 164.54 deg/RIU, 199.59 deg/RIU, and 253.68 deg/RIU, respectively, for cyanogen, phosgene, ethanol, and propane gas. Additionally, the values of the detection accuracy (DA), the figure of merits (FoM), and full-width at half-maximum (FWHM), which are 0.17 deg −1 , 43.30 RIU −1 , and 5.86 deg, respectively, were also obtained. The proposed structure’s distribution of the electric field propagation under resonant conditions was also depicted. Further tests were done to see how the thickness of the Ag and other layers affected the overall sensitivity sensor for the four different gas types. The proposed layered Ag/MgO/Si arrangement had the highest overall sensitivity in distinguishing propane gas from other hazardous gases.