Enhanced the sensing sensitivity of the metamaterial absorbers with patterned convex graphene in the terahertz

Abstract

In this paper, a patterned graphene metamaterial terahertz absorber is theoretically designed. The proposed absorber consists of a gold layer, a dielectric layer of SiO₂, and graphene. The sensing sensitivity of the proposed absorber is simulated for the absence and presence of a square convex nanostructure, trapezoidal convex nanostructure, and rounded convex nanostructure. The sensitivity comparison between convex and absent convex nanostructures is studied, compared to no convex nanostructure, the simulated results show that the sensing sensitivity can be improved with the convex nanostructures, it is found that the absorber has two obvious absorption peaks, and it is insensitive to TE and TM polarization, and the maximum sensitivity corresponding to low-frequency and high-frequency modes is 0.911 THz RIU⁻¹ and 1.561 THz RIU⁻¹, respectively. Our work will play an important role in improving the sensing sensitivity of the graphene metamaterial absorber. Meanwhile, it can also greatly promote the application of biological sensing, modulation, integrated photodetectors, frequency selectors, sensors, filters and so on.