Performance Comparison of Lossy Mode Resonance Refractive Index Sensors on Structures Based on Graphene and MoS2

Abstract

Abstract 2D materials such as graphene and MoS2 have a crucial role in improving the performance of optical sensors. In this work, we investigated a lossy mode resonance (LMR) sensor composed of MgF2 and 2D materials. The transfer matrix method has been chosen to determine the reflectance curve of the sensor with different thicknesses of MgF2 and 2D materials. The computational results show that the LMR sensor generated with s-polarized light has a better resonance. The existence of exciton in MoS2 also has a very dominant contribution to the resulting resonance. There are two absorption peaks around the wavelengths of 610 and 652 nm which are caused by the presence of excitons A and B in MoS2. When graphene- and MoS2-based chips are compared, MoS2-based chips display a wider detection range with better signal stability. A sensitivity of 70.37°/RIU can be achieved with MgF2 (200 nm)/MoS2 (5 layers). In addition, the proposed LMR sensor has a penetration depth that is two times higher than conventional SPR sensors, making it possible to replace SPR sensors which rely heavily on gold as their transducer.