H2S gas sensor based on Weyl semimetal and 1D porous silicon photonic crystal

Hydrogen sulfide (H2S) is a highly toxic and hazardous gas commonly found in refineries, petroleum, and natural gas environments. It is also explosive and heavier than air. We present a gas sensor designed to detect H2S in varying concentrations using a Weyl semimetal (WSM) combined with a one-dimensional porous silicon photonic crystal (PSi-1DPC). In our sensor, the gas is contained in the cavity formed between the WSM layer, which serves as a plasmonic material, and the PSi-1DPC. The sensor utilizes Tamm plasmon polaritons (TPPs) generated at the interface of the WSM and PSi-1DPC to detect minute changes in H2S concentration. We investigate the impact of the geometrical parameters of the sensor and the intrinsic characteristics of the WSM layer on its efficiency to identify the optimal structure. Our results indicate that the proposed sensor operates effectively in both transverse electric (TE) and transverse magnetic (TM) modes, with higher efficiency observed in the TE mode. The sensor achieves a maximum sensitivity of 152.980 µm/RIU, a figure of merit of 435.356×103 1/RIU, and a limit of detection of 1.144×10-7 RIU. Therefore, employing the WSM layer as a plasmonic material to excite the TPP modes presents a promising solution for the highly sensitive and accurate detection of H2S gas in related industries.