Performance Enhancement of Surface Plasmon Resonance Biosensors Based on Noble Metals-Graphene-WS2 at Visible and Near-Infrared Wavelengths

In this paper, some biological sensors based on surface plasmon resonance are proposed at visible and near-infrared wavelengths and their performance is improved. The structure of these sensors includes metals, graphene, and 2D transition metal dichalcogenides (TMDCs). Metals such as gold, silver, and copper and a different number of graphene and WS 2 layers are investigated for improving the performance of this sensor. The sensitivity of this sensor is studied at the three wavelengths of 633 nm, 660 nm, and 785 nm. In addition, by using the particle swarm optimization (PSO) method, reflectivity is optimized in terms of structural parameters. The best absorption belongs to gold with a reflectivity of 1.3383 × 10 −5 (a.u). The results show that this structure which includes metals, graphene, and WS 2 has a better performance in near-infrared wavelengths than in visible wavelengths. In this paper, the angular sensitivity and the figure of merit can reach as high as 336 (Deg/RIU) and 48.27 (1/RIU), respectively, as obtained by the optimized structure.