Theoretical modeling and design of a graphene-based tunable metamaterial perfect absorber for broadband and narrowband terahertz applications

Metamaterial-based perfect absorbers operating in the terahertz range have been a topic of great interest to researchers because of their diverse applications. The number of applications is so great that a specific absorber is specific to only its intended application. Therefore, a metamaterial-based perfect absorber that can be used for different applications depending on the environment it is to be used will be a highly appreciative innovation. This article presents a polarization-independent, wide-angle, angle-stable, and tunable graphenebased metamaterial perfect absorber that can be used for multiple narrowband and broadband applications. Numerical simulations were carried out on commercially available finite element method-based software to verify the presented claims. The proposed absorber showed a highly tunable absorbance spectrum of 3.1 THz between the frequencies 6.4 THz to 9.5 THz, which is greater than the bandwidth of most of the broadband absorbers being used in this frequency regime. This large tunable region of the proposed absorber allows it to be used for narrowband and broadband applications such as energy harvesting and material spectroscopy.