Wavelength-selective metamaterial absorber based on 2D split rhombus grating for thermophotovoltic solar cell

Promising application prospects and excellent characteristics of metamaterials are currently under intensive research work all over the world. In this paper, novel wavelength selective metamaterial absorber based on 2D split rhombus grating is numerically proposed and analyzed. The suggested metamaterial absorber is made of molybdenum metals with dielectric spacer of Magnetic Florid (MgF 2 ). The effects of the design parameters are studied to improve the absorption of the reported metamaterial absorber. Additionally, the inductor and capacitor (LC) model is investigated to understand the physics beyond the absorption of the studied design. The finite difference time domain method is used to obtain the modal analysis and absorption characteristics of the metamaterial structure. Perfect absorption is achieved through studied wavelength range from 300 to 20,000 nm with high photon-to-heat efficiency of 81.71% at 1000 K. The absorption enhancement is due to the coupling between the surface plasmon polariton, Fabry–Perot resonance, and magnetic polariton. It is also found that the achieved absorption is insensitive to the oblique incidence from θ = 0° to 60° for the transverse magnetic (TM) and transverse electric (TE) waves. Therefore, the suggested absorber has a good potential for using in solar energy harvesting and conversion systems.