Mathematical and Parametric Analysis of Graphene/Graphite based Stacked-Disk Metal-free Cone Shaped Wide band Tera hertz Absorber

Abstract

Abstract In this article, a wide band Tera hertz metal free absorber has been designed and numerically analysed. Graphite/Graphene disk is stacked which is surrounded by a low permittivity substrate. Further a substrate is placed over the stacked Graphite sheet, which acts for resonance cavity. A conical Shaped Structure is obtained by placing such type of model over one another by reducing the outer radius only. The resonating mode of dielectric covered substrate and Graphite or Graphene sheet are matched for wide band absorber. The result has also been calculated by analysis of its Equivalent Transmission line model. The result obtained from transmission line and from numerical analysis have been compared. These result have also been verified using MATLAB and CST software. The proposed absorber provides a simple and compact structure by polarisation. By changing the incident angle of 750 of proposed absorber polarisation variation provide a higher-level absorber in same plane. A Graphene disk is used at the top to change the chemical potential of absorber so that different tuning is provided for the response of wide band absorber. The chemical potential for broad band absorber lies between 0 and 0.21 eV, while for narrow band absorber, it is higher than 0.21 eV. If chemical potential is greater than 0.21 eV, it separates the lower order band that is provided by stacked Graphite sheet. This enhances the working capacity of proposed metal free wide band absorber.