Polarization- and angle-insensitive ultrabroadband perfect metamaterial absorber for thermophotovoltaics

Abstract

We report an ultrabroadband perfect metamaterial absorber, comprising a two-dimensional array of a hemi-ellipsoid shaped metallo-dielectric multilayered structure. What we believe, to the best of our knowledge, is an unprecedented average absorbance of ∼ 99 % is theoretically demonstrated in the 300 to 4500 nm spectral range at normal incidence. We use 20 pairs of molybdenum–germanium metallo-dielectric layers with tungsten as the ground metal placed on a silicon substrate. Our design is polarization-independent as well as angle-insensitive (up to 60°), making it a perfect “superabsorber.” Theoretical modeling based on effective medium theory validates our full-wave simulation results. The figure-of-merit calculations suggest that our superabsorber can outperform recently reported broadband absorbers. The proposed design has potential application in thermophotovoltaics for solar energy harvesting.

Review of Broadband Metamaterial Absorbers: From Principles, Design Strategies, and Tunable Properties to Functional Applications

“…[ 385 ] A hemi‐ellipsoid shaped metal‐dielectric multi‐layer structure of BMA achieves an unprecedented 99% average absorption in the spectral range of 300–4500 nm at normal incidence. [ 386 ] Some multi‐layer stacked designs of BMAs possess a more specific configuration in terms of appearance, such as a metal‐dielectric (Ni/SiO 2 ) stacked BMAs with a half cylinder cross section, [ 387 ] where the average absorption of the device exceeds 90% at normal incidence in the visible spectrum. Zhao et al.…”

“…[385] A hemi-ellipsoid shaped metal-dielectric multilayer structure of BMA achieves an unprecedented 99% average absorption in the spectral range of 300-4500 nm at normal incidence. [386] Some multi-layer stacked designs of BMAs possess a more specific configuration in terms of appearance, such as a metal-dielectric (Ni/SiO 2 ) stacked BMAs with a half cylinder cross section, [387] where the average absorption of the device exceeds 90% at normal incidence in the visible spectrum. Zhao et al presented a BMA consisting of a curved periodic metaldielectric stack, [388] where the visible to MIR region allows an expected incidence of transverse magnetic polarization waves with an average light absorption of about 90%.…”

Thin Germanium Waveguide-Array-Like Absorber Based on Localized Resonance

“…Under the assistance of the metal substrate as a reflecting mirror, it is easy to realize perfect absorption based on the resonance from each unit. With a thin thickness, a MA can be scaled to operate in different frequency bands from the microwave to the ultraviolet [6].The central working frequency can be adjusted by introducing some tunable materials or mechanisms [7], and the working bandwidth can also be designed to be broadband based on various mechanisms, especially by introducing several different resonant modes into one unit cell [8]- [12]. MAs have been applied in various areas, such as electromagnetic and infrared cloaking [13], [14], photoelectric detection and imaging [15]- [17], solar energy utilization [18]- [20] and sensitive sensing [21]- [23].…”

Polarization‐independent dual narrow‐band perfect metamaterial absorber for optical communication

“…For instance, based on the coupling of Mie scattering, electric dipole, and surface plasmon polaritons resonances, Yun et al proposed an ultrabroadband metamaterial absorber 22 . Chowdhary et al reported an ultra‐broadband perfect metamaterial absorber consisting of a two‐dimensional (2D) array of metal‐dielectric multilayer structures in the shape of a semi‐ellipsoid 23 . In the previous works, 24–26 polarization tunable multi‐band terahertz resonant absorbers were developed using anisotropic microstructure arrays.…”

“…22 Chowdhary et al reported an ultra-broadband perfect metamaterial absorber consisting of a two-dimensional (2D) array of metal-dielectric multilayer structures in the shape of a semi-ellipsoid. 23 In the previous works, [24][25][26] polarization tunable multiband terahertz resonant absorbers were developed using anisotropic microstructure arrays. However, few previous works have paid attention to polarization-independent ultra-narrowband absorbers in the optical communication band.…”