Large‐Area, Broadband, Wide‐Angle Plasmonic Metasurface Absorber for Midwavelength Infrared Atmospheric Transparency Window

Abstract

High performance broadband absorbers in the midinfrared atmospheric transparency windows are of great importance in various applications, such as energy harvesting, photodetection, radiative cooling, and stray light elimination. In recent years, great efforts have been made to develop absorbers using plasmonic nanostructured resonators in the infrared regime. Although these approaches promise distinct advantages in performance enhancement, they still suffer several obstacles, e.g., limitations on sample size, bandwidth, and fabrication throughput. Here, a large‐area broadband wide‐angle plasmonic metasurface absorber with nearly perfect absorption over the range of midwavelength infrared atmospheric transparent window (3–6 µm) is proposed and experimentally demonstrated. The metasurface absorber is basically comprised of a monolayer of sub‐micrometer‐sized polystyrene spheres self‐assembled on an opaque metallic substrate and coated with metal–insulator–metal three‐layer thin film, and fabricated by using simple, low‐cost self‐assembly techniques. Numerical simulation analyses not only corroborate the experimental observations, but also discover that such broadband absorption effect is attributed to hybrid plasmonic multiple resonances. The combination of the significant light absorption effect, compact design, and high‐yield self‐assembly fabrication process suggests that the proposed absorber has wide prospect application in integrated optical and optoelectronic systems.

Photonic Multilayer Structure Induced High Near‐Infrared (NIR) Blockage as Energy‐Saving Window

“…Metasurfaces based on subwavelength scale nanostructure absorb NIR by using Mie resonance. [4][5][6][7][8][9][10][11][12][13][14][15][16] However, the absorbed solar energy acts as with calculated results. The NIR-blocking effectiveness of the designed multilayer film exceeds those of previously-reported other technologies such as metasurfaces, D/M/Ds, thin-film structures and organic coatings by employing an extra TiO 2 back reflector layer.…”

“…NIR-blocking films have been developed using several techniques such as metasurface, [4][5][6][7][8][9][10][11][12][13][14][15][16] D/M/D films, [24][25][26][27][28] and thin films, [41][42][43] organic coatings [44][45][46][47][48][49][50][51] (Table 1). NIR blocking metasurfaces are divided into opaque and transparent types.…”

Broadband metamaterials and metasurfaces: a review from the perspectives of materials and devices

“…The proposed structure shows an averaged absorption of 85% in the visible spectral range. In several studies, it has been demonstrated that deposition of additional layers onto existing resonators can provide better admittance-matching, resulting in higher absorber performance [99][100][101]. In [100], silicon carbide and silicon dioxide (SiO 2 ) are used as anti-reflection layer on tungsten (W) cylinder array so that over 95% absorption at 200-900 nm wavelengths range can be achieved, which is much broader than the case of bare W cylinder array.…”

Detailed Experiment-Theory Comparison of Mid-Infrared Metasurface Perfect Absorbers

“…For the mid-infrared wavelengths, MIM metasurfaces ( Figure 1) could be designed as photo-thermal energy converters which convert luminous IR light into heat [2][3][4]. Broadband mid-IR absorbers were demonstrated by a metal-coated polystyrene micro-bead colloidal lithography, which also have a wide-angle performance [5]. The MIM metasurfaces with metallic nano-/micro-structures on the top surface require only one lithography step [1].…”