High-Performance Metamaterial Light Absorption from Visible to Near-Infrared Assisted by Anti-Reflection Coating

Abstract

This study experimentally demonstrates two types of ultra-broadband metamaterial absorbers with high performance in the visible-to-near-infrared range by using different anti-reflection coatings (i.e., SiO2 and Si3N4) and a multi-subcell Ti-SiO2-Ti metasurface. Compared to the bare metamaterial nanostructure, the absorption bandwidth of the coated metasurfaces exhibit increases of 594 nm and 1093 nm, respectively. Such improvements benefit from nearly perfect impedance matching to the free space enhanced by the anti-reflection coating, thin film interference, and excitations of different surface plasmon resonances. As a result, the absorber with SiO2 coating exhibits a measured bandwidth with an absorption of 0.9 ranging from 502 nm to 1892 nm, while the absorber with Si3N4 coating further broadens the bandwidth from 561 nm to 2450 nm. The measured average absorptions for both cases remain above 95% and 87%, respectively. Moreover, both nanostructures are robust to large incident angles of up to 60° for both TE and TM modes. Our findings highlight the promising potential of these absorbers for various applications, including solar energy harvesting, thermal emitters, and photodetectors.

Ultra-wideband and wide-angle metamaterial absorber for solar energy harvesting from ultraviolet to near infrared

“…In contrast, the proposed MA shows a significant increase in absorption throughout the wavelength range, and the average absorption is even increased by 49.96%. In addition, to visualize the advantages of the proposed MA, table 1 gives a comparison between our work and others [28][29][30][31][32][33][40][41][42][43][44] in terms of the bandwidth, the average absorption, and the overall thickness of the absorber. As seen from the table, our designed MA not only improves the absorption efficiency and bandwidth but also further reduces the overall thickness of the device.…”

“…Yu et al designed a disk-shaped absorber using TiO 2 and TiN to achieve a 1264 nm broadband with an average absorption rate of 95.68% [21]. Wu et al utilized Ti and SiO 2 to achieve an absorber with an average absorption of 96.2% in the wavelength range of 440-2124 nm [29]. Huang et al designed an absorber consisting of an a-Si spacer layer and periodic square arrays on a Ti substrate, achieving an average absorption of over 95% in the range of 300-2000 nm [30].…”

Asymmetric Orthogonal Metasurfaces Governed by Toroidal Dipole Bound States in the Continuum

“…In recent years, significant research attention has been focused on metasurfaces [1][2][3][4]. These surfaces are usually composed of artificial electromagnetic materials made from subwavelength-scale dielectric nanostructures.…”

Asymmetric Orthogonal Metasurfaces Governed by Toroidal Dipole Bound States in the Continuum

“…In recent years, significant research attention has been focused on metasurfaces [1][2][3][4][5][6][7]. These surfaces are usually composed of artificial electromagnetic materials made from subwavelength-scale dielectric nanostructures.…”