Ultra-broadband absorber from visible to near-infrared using plasmonic metamaterial

Abstract

We propose a design of an ultra-broadband absorber based on a thin metamaterial nanostructure composed of a periodic array of titanium-silica (Ti-SiO) cubes and an aluminum (Al) bottom film. The proposed structure can achieve nearly perfect absorption with an average absorbance of 97% spanning a broad range from visible to near-infrared (i.e., from 354 nm to 1066 nm), showing a 90% absorption bandwidth over 712 nm, and the peak absorption is up to 99.8%. The excitation of superior surface plasmon resonance combined with the resonance induced by the metal-insulator-metal Fabry-Perot (FP) cavity leads to this broadband perfect absorption. The polarization and angle insensitivity is demonstrated by analyzing the absorption performance with oblique incidences for both TE- and TM-polarized waves. In addition, we discuss the impact of various metal materials and geometry structure on absorption performance in detail. The proposed broadband metamaterial absorber shows a promising prospect in applications such as solar cell, infrared detection, and imaging. Moreover, the use of a thin titanium cap and an aluminum film instead of noble metals has the potential to reduce production cost in applications.

Ultra-Broadband High-Efficiency Solar Absorber Based on Double-Size Cross-Shaped Refractory Metals

“…When the wavelength was 1276.83 nm, the absorption rate reached the highest, which was about 96%. In Table 1, we cited some examples of broadband high absorption using refractory metals in the past [49][50][51][52][53]. By comparison, we could conclude that the absorption effect of our absorber was better.…”

“…Nanomaterials 2020, 10, x FOR PEER REVIEW 4 of 11 Table 1. Comparison between the different absorber designs proposed in previous studies [49][50][51][52][53].…”

Broadband mid-infrared perfect absorber using fractal Gosper curve

“…Compared with the unit cell size and length, the thickness (t 2 ) of the resonator has a relatively small influence on the absorption and bandwidth. As the thickness increases, it induces a weaker coupling, but as the thickness increases and it induces a weaker coupling [47]. Thus, the t 2 need to be compromised between high absorbance and broad bandwidth.…”

Broadband Microwave Absorption by Logarithmic Spiral Metasurface

“…The absorption of electromagnetic waves has continuously drawn attention due to various applications such as stealth, reduction in radiation exposure, and solar energy related technologies. Since the advent of metamaterials [1][2][3], a large number of studies have been carried out to explore the possibility of absorbing electromagnetic waves by using metamaterials [4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19][20][21][22][23]. In particular, several designs of metamaterials for achieving broadband absorption have been proposed, such as the dispersion-engineered metamaterial [24,25] and the pyramid metamaterial [26,27].…”