Graphene-based Tunable Terahertz Metamaterial Absorber with High Absorptivity

In this paper, we present a graphene-based metamaterial absorber, which is comprised of three layers with a meta-dielectric-graphene structure. Numerical simulations demonstrate that two high absorptivity of 99.9% at 6.62THz and 98.9 % at 9.36THz are produced, respectively in terahertz band, and the resonance amplitude and frequency of the absorber can be controlled flexibly by changing the Fermi level of graphene, and when the relaxation time of graphene changes, the absorption intensity of the metamaterial absorber can be individually controlled. In addition, we show the thickness of the intermediate dielectric layer of the proposed absorber affects the absorptivity, which is conducive to determine the initial processing parameters of the absorber. The study demonstrates that the graphene-based metamaterial absorber proposed in this paper has a simple structure and is easy to fabricate, moreover, it is very convenient to achieve the flexible tuning of metamaterial absorbers by biased voltages or chemical dopings, and it provides an important guide for designing dual-band absorbers with high absorptivity.