Numerical Study of a Wide-Angle and Polarization-Insensitive Ultrabroadband Metamaterial Absorber in Visible and Near-Infrared Region

Abstract

An ultrabroadband metamaterial absorber structure based on a periodic array of metallic-dielectric multilayered conical frustums is numerically investigated and proposed. The metamaterial absorber indicated an absorptivity of higher than 90%, which covered the visible and near-infrared region at 480-1480 nm, and a relative absorption bandwidth of 102%. The high absorptivity can be maintained with large incident angles up to 60°under both transverse electric and transverse magnetic polarizations. Furthermore, the proposed absorber exhibits polarization insensitivity owing to its rotational symmetry structure. Compared with the previously reported ultrabroadband metamaterial absorbers, the design in this work indicates high practical feasibility in terms of a compact structure for a large bandwidth, a wide incident angle, and polarization insensitivity, thereby suggesting its promising application, for example, in solar cells and thermal emitters.

Elliptical metallic rings-shaped fractal metamaterial absorber in the visible regime

“…To broaden the absorption spectrum, varieties of device configurations, including multilayer stacking of resonant elements in the vertical direction 41 , perpendicularly standing nanowires 42 and multiple resonators using in-plane arrangement 43 , have been used. Within the context, Lai et al .…”

“…Hoa et al . 41 reported ultra-broadband metamaterial absorber with high absorptivity (> 90%) in the visible and near-IR regimes (480–1,480 nm) by adopting symmetrical metasurfaces in a periodic arrangement of multilayered conical frustums. A nearly similar type of 2D metamaterial absorber 31 based on a dielectric-nickel grating structure was numerically investigated to demonstrate nearly perfect absorption at normal incidence in the visible regime (~ 400–800 nm).…”

“…However, complexities in structures introduce difficulties in manufacturing and applications. For example, the coalescing of multilayer absorbers with industrial technologies becomes challenging, owing to the bulky size, high manufacturing cost, and the use of noble metals 26 , 41 – 43 . In addition, though the use of multi-resonance approach remains simpler to fabricate the relevant device in comparison to the multilayer kind, the former method is still far behind the latter type owing to limited absorption in a specific frequency band 44 , 46 .…”

“…To broaden the absorption spectrum, varieties of device configurations, including multilayer stacking of resonant elements in the vertical direction 41 , perpendicularly standing nanowires 42 and multiple resonators using in-plane arrangement 43 , have been used. Within the context, Lai et al 43 used Al/SiO 2 /Al kind of sandwiched structures in a simple absorber with the integration of hybrid dual-resonators, and achieved polarizationinsensitive absorption of above 95% in the 450-600 nm spectral range.…”

“…Within the context, Lai et al 43 used Al/SiO 2 /Al kind of sandwiched structures in a simple absorber with the integration of hybrid dual-resonators, and achieved polarizationinsensitive absorption of above 95% in the 450-600 nm spectral range. Hoa et al 41 reported ultra-broadband metamaterial absorber with high absorptivity (> 90%) in the visible and near-IR regimes (480-1,480 nm) by adopting symmetrical metasurfaces in a periodic arrangement of multilayered conical frustums. A nearly similar type of 2D metamaterial absorber 31 based on a dielectric-nickel grating structure was numerically investigated to demonstrate nearly perfect absorption at normal incidence in the visible regime (~ 400-800 nm).…”