Improved the quality factor and sensitivity of a surface plasmon resonance sensor with transition metal dichalcogenide 2D nanomaterials

In this paper, design and modeling of a surface plasmon resonance (SPR) sensors using transition metal dichalcogenide (TMDC) 2D nanomaterials such as tungsten sulfide (WS₂) and graphene with the improvements of the sensitivity and the figure of merit (FoM) are demonstrated. The proposed sensors are based on Kretschmann configuration for the obtaining of the reflectivity using the transfer matrix method (TMM) and Fresnel equations. A monolayer of nickel (Ni) was added between WS₂ layers and graphene layers to enhance the sensitivity (S) and FoM of our proposed sensor. The reported sensor exhibits a good angular sensitivity which is improved to the maximum value of 243.31°/RIU. It is noted the SPR sensor sensitivity changes with the variation of the WS₂ and graphene layer numbers. Full width half maximum (FWHM) values are minimized to be 7.15°; then, the FoM is reached to be 34.03 RIU⁻¹ which gives better sensing properties in comparison with other published articles.