Tunable dual-band perfect metamaterial absorber based on monolayer graphene arrays as refractive index sensor

In this study, we propose and numerically investigate a tunable dual-band perfect metamaterial absorber that is based on monolayer graphene arrays in the terahertz region. The proposed structure of the metamaterial absorber consists of a perforated graphene disk array on top of a gold ground plate spaced by a SiO(2)dielectric substrate. The absorber achieves almost 100% absorption peaks at 4.7 and 10.7 THz. The resonance frequency and intensity can be adjusted by controlling the graphene conductivity and the structural parameters. Moreover, the absorber is insensitive to the variation in incident angle. The presented absorber can work as a refractive index sensor and the sensitivity reaches 0.67 and 2.33 THz/RIU. Furthermore, it has potential applications in communication, and photovoltaic devices because of its flexible design and stable properties.