Designing a Broadband Terahertz Metamaterial Absorber Through Bi-Layer Hybridization of Metal and Graphene

This study proposes a broadband metamaterial absorber that integrates metal and graphene metasurfaces sandwiched with dielectric spacers to create a cavity resonant effect. The structure comprises a gold-based patterned metasurface as the top layer, a graphene-based patterned metasurface as the middle layer, and a grounded gold film with SiO2 spacers between them. The absorptance bandwidth is significantly expanded through the plasmonic hybridization of surface, cavity, and gap plasmon resonances. We establish an effective hybrid metal-dielectric-graphene-based metasurface using the adjustable chemical potential and optimizing structural parameters. Numerical simulations validate its efficacy, demonstrating a maximum absorptance value of 98.9