In this paper, we demonstrate the design of a polarization-independent wideband absorber of light that consists of a perforated graphene sheet on top of a lossless dielectric spacer placed on a metallic reflector. The single layer absorber is duly designed based on impedance matching concept. The simulated results indicate that the structure produces 0.98 THz broad absorption from 1.80 THz to 2.72 THz with absorptivity larger than 90% at the normal incidence. The electromagnetic (EM) field distributions and the plots of surface power loss density have been illustrated to explain the absorption mechanism of the structure. The variation of chemical potential from 0.8 to 1.2 eV keeps 90% absorption bandwidth as much as 1 THz band. The polarization-insensitive feature and the properties under oblique incidence are also investigated. Finally, the interference theory is used to analyze and interpret the broadband absorption mechanism.
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