Investigation of 2D nanomaterials on Indium Phosphide-based plasmonic devices for sensing in the optical communication band

Abstract

2D nanomaterials have gained much attention because of better molecular interaction with the target surface. It is the study of the effect of these biorecognition layers that we present in this paper, over the Indium Phosphide (InP) layer with different plasmonic metals coated on a glass prism. We consider Molybdenum disulfide, Black Phosphorus, and Fluorinated Graphene (FG) to bio-functionalize the top surface of the proposed sensing devices. InP is used as a dielectric material that enhances the overall performance parameters in terms of sensitivity and Figure of Merit (FOM). The optical output is evaluated by capturing the reflected light from a prism-based coupling arrangement. Simulations are carried out for the optimization of layer thicknesses of various plasmonic metals (Gold (Au), Silver (Ag), and Aluminum (A1)) followed by studying the effect of three different 2D nanomaterials, over the top surface of the proposed device. Finally, the results of the proposed configuration are compared, and it is found that Ag-InP-FG shows the best sensitivity and FOM of 131 0/RIU and 655 RI$\mathrm{U}^{-1}$ respectively. Such appreciable numbers of performance parameters provide a potential for the proposed plasmonic devices to be employed in the sensing applications at the nanoscale.