Optimal terahertz shielding performances of flexible multilayer screens based on chemically doped graphene on polymer substrate

The shielding performances of multilayer screens made of laminated graphene sheets with flexible polymeric interlayer depend on several factors such as thickness of the polymer interlayers, number of laminated graphene sheets, electron transport properties of graphene, and frequency range. Previous studies have highlighted that the frequency dependent graphene conductivity is a function of the charge carrier density, mobility and quantum scattering time, and it is strongly affected by doping and fabrication route. This paper is aimed at the analysis of the shielding performances of laminated graphene/polymer multilayers at terahertz, in order to provide insights on the optimum shield design as a function of frequency. The proposed simulation model accounts for the frequency dispersive properties of the graphene monolayer and of the polyethylene terephthalate (PET), which is considered as flexible polymeric interlayer material. The optimal choice of the substrate thickness is discussed in order to achieve the maximum value of the shielding effectiveness (SE) in the terahertz frequency range. The proposed design procedure is applied to three multilayer shield configurations, which are made of different types of chemically doped graphene. The computed frequency spectra of the shielding effectiveness up to 10 THz highlight the shielding performances of the considered samples.