Spectral Response and Wavefront Control of a C-Shaped Fractal Cadmium Telluride/Silicon Carbide Metasurface in the THz Bandgap

Abstract

We report theoretical investigations on the spectral behavior of two fractal metasurfaces, performed in the 3–6 THz frequency window (5–10 μm equivalent wavelength window), under illumination with both linear and circular polarization state fields. Both metasurfaces stem from the same tree-like structure, based on C-shaped elements, made of cadmium telluride (CdTe), and deposited on silicon carbide (SiC) substrates, the main difference between them being the level of structural complexity. The simulated spectral behavior of both structures indicates the tunability of the reflection spectrum by varying the complexity of the tree-like structure.

Towards High-Efficiency Photon Trapping in Thin-Film Perovskite Solar Cells Using Etched Fractal Metadevices

“…Such control over a structure's properties, along with recent advances in micro and nanofabrication technologies [33][34][35][36], has allowed the design and fabrication of metasurfaces with specific electromagnetic properties, tailored for a wide range of applications, in specific ranges of the electromagnetic spectrum. For GHz and THz domains, metasurface designs have been demonstrated for applications such as imaging [37,38], wave front shaping [39,40], high-speed communication [41,42], and sensing [43,44]. In the visible domain, metasurfaces have been designed and tested as devices for beam shaping [45][46][47][48], metalenses [49][50][51][52], and light-trapping structures for thin-film solar cells [53][54][55][56].…”