Lithography-free high sensitivity perfect absorption based on Graphene/ α-MoO3/SiC and Tamm plasmonic structure

In this paper, we propose a tunable perfect-absorption lithography-free refractive index sensor structure, which couples the Tamm phonon polariton (TPhP) mode and Graphene/alpha-MoO3/SiC (GMS) mode. By aligning the modal frequencies of TPhP and GMS, the coupling of the two modes is realized with perfect absorption. We utilize the transfer matrix method (TMM), resonance equation and coupled mode theory (CMT) to theoretically analyze the absorption of different modes and apply the structure to refractive index sensor. By modulating the structure parameter, the sensitivity of the sensor can be as high as 6 mu m/RIU. This work could contribute to several fields such as refractive index sensors, photodetectors, absorbers, and energy harvesting devices.