Controlling THz Absorption Properties of Metamaterials Based on Graphene

With great potential for applications in fields such as heat radiation, energy harvesting, and biochemical and molecular sensing, the terahertz (THz) metamaterial (MM) absorber has attracted great interest and is the subject of intensive study. Research on developing intelligent metamaterials which can control absorption properties is of particular importance. Based on the computational and simulation technique, we propose a design of metamaterial capable of absorbing electromagnetic waves in the THz frequency region by exploiting a fishnet-structured graphene layer. The investigation results demonstrate that it is possible to determine the desired resonance frequency in the THz region by a suitable set of structural geometry parameters. More interestingly, the absorption of the designed MM can be controlled by an external electric field through an applied DC bias voltage to the graphene layer. Simulation and calculation results show that with a voltage of 594 V, the absorption of MM can reach 99% at 6.125 THz. On the contrary, if there is no applied voltage, the THz electromagnetic wave is almost completely reflected. The proposed graphene-integrated metamaterial absorber can function as a switchable absorption window that can be used for diverse THz smart technologies.