An Ultra-Wideband Metamaterial Absorber with High Fractional Bandwidth for Solar Energy Harnessing in the Visible Spectrum

This study shows the design and analysis of a new absorber metamaterial based on the Si-Ni-Si structure for application in solar energy harnessing in the visible spectrum. The simulation is performed using the Computer Simulation Technology (CST) software, with a selected frequency range of 350-800 THz, which effectively encompasses the visible spectrum. The design techniques are illustrated step-by-step, accompanied by graphical representations of absorption for each phase. The metamaterial absorber demonstrates a high absorption level, exceeding 95%, across the frequency range of 350-800 THz. It achieves near-perfect absorption from the 424.25- 603 THz frequency spectrum, reaching over 99% absorption in that range. The peak absorption is 99.527% at a frequency of 505.7 THz in the visible spectrum. The absorber is simulated using various polarized TE, TM, and TEM waves, but no substantial alteration is detected. The absorptivity curve remains unchanged during TE and TM mode analysis making the material polarization insensitive. The absorber has angular stability up to 520. The suggested absorber shows a substantial fractional bandwidth of 72.26% and an absolute bandwidth of 450 THz. Due to its numerous advantages, the suggested absorber is an ideal choice for harnessing solar energy. It may serve as a dependable renewable resource to meet the growing energy needs of the worldwide population.