Broadband metamaterial absorber in the visible region using a petal-shaped resonator for solar cell applications

Abstract

We present an efficient broadband metamaterial (MM) solar spectrum absorber with a wide incident angle and polarization-insensitive absorption. Proposed absorber is a three layers absorber in the form of a metal-dielectric-metal (resonator) structure. We use a single dielectric layer of silicon dioxide (SiO2) between the metasurface (petal-shaped) and the lower layers of tungsten (W) metal. We obtained around 99% average absorption from 400 nm to 750 nm and a near-unity absorption at 572.23 nm wavelength. The unit cell structure shows 99% absorption from wavelengths from 456.62 nm to 677.73 nm and has an ultra-wide bandwidth (221.11 nm). For both the transverse magnetic (TM) and transverse electric (TE) modes, this design demonstrates the wide-angle absorption up to 60°. These properties can be used for thermo-photovoltaics, solar cells, and energy harvesting devices. In addition, geometrical studies are also carried out to obtain the optimized physical dimensions of the proposed absorber. We also analyze the weighted absorption under AM1.5 solar luminosity by changing the thickness parameter of the SiO2 layer. Short circuit current density (Jsc = 26.41 mA/cm2), open-circuit voltage (Voc), fill factor, and conversion efficiency are also observed for the proposed absorber. These results reveal their utility for solar cell applications. © 2022 Elsevier B.V.