# A Metallic Glass-Based Dual-Band-Selective Emitter with Near-Perfect Absorption in Atmospheric Windows

## TL;DR

A new trilayer structure using metallic glass achieves near-perfect absorption in two infrared bands, promising for heat dissipation and cooling.

## Contribution

A lithography-free metallic glass-based structure enables dual-band-selective absorption in MWIR and LWIR atmospheric windows.

## Key findings

- The MGIM structure achieved 96.7% absorptance at 3.9 μm in the MWIR band.
- The structure exhibited 98.8% absorptance at 10.8 μm in the LWIR band.
- The MGIM structure outperformed typical MIM emitters in radiative cooling.

## Abstract

A new trilayered structure design of metallic glass film
was proposed
and demonstrated to achieve near-perfect dual-band-selective absorptions
within mid-wavelength infrared (MWIR) and long-wavelength infrared
(LWIR) bands in atmospheric windows. A metal–insulator–metal
(MIM) structure was used as a selective absorber for decades; however,
due to the highly reflective properties of metal in the infrared region,
the structure was difficult to apply within the mid- and long-infrared
region. By applying the metallic glass film as a top layer, the asymmetric
metallic glass–insulator–metal (MGIM) structure could
display remarkably high absorptance in the mid-IR region, a distinct
feature that a conventional metal–insulator–metal (MIM)
structure could not achieve. In addition, the MGIM structure exhibited
outstanding omnidirectional properties. The fabricated MGIM structure
exhibited near-unity absorptions within MWIR and LWIR atmospheric
windows, with an absorptance of 96.7% and 98.8% at peak wavelengths
of 3.9 and 10.8 μm, respectively. These remarkable characteristics
of the AlNiY-based MGIM structure make it highly promising for heat
dissipation applications. The MGIM structure showed better radiative
cooling performance than typical MIM emitters and an ideal broadband
emitter. Furthermore, compared with other dual-band emitters that
utilize complex metamaterial structures, the lithography-free process
of our approach dramatically reduces the cost and simplifies the processes.