posted on 2024-03-11, 06:29authored byJoon-Soo Lim, Namkyu Lee, Taehwan Kim, Injoong Chang, Juyeong Nam, Hyung Hee Cho
Tailoring the optical properties of metamaterials is
crucial for
improving the performance of infrared (IR) applications. Generally,
IR camouflage materials are required to have low IR-emission properties
for the detected bands (3–5 and 8–12 μm), in which
IR detection is accomplished. However, the heat residue by suppressed
thermal radiation degrades the thermal dissipation capacity and thermal
stability of IR camouflage materials. Herein, a multilayer metal–dielectric–metal
(MDM) selective emitter with high IR-emission performance in the undetected
band for thermal management and low IR-emission performance in the
detected band for IR camouflage is introduced. Compared to a conventional
selective emitter and a low-emission material (Au film), the multiresonance
selective emitter exhibited 125 and 2910% increases in heat dissipation
within the undetected band, respectively. In addition, the proposed
camouflage material exhibited a substantial reduction in emissive
energy within the detected bands of 3–5 and 8–12 μm,
with reductions of 72 and 83%, respectively, compared to that of a
high-emission surface. The effectiveness of our IR camouflage was
demonstrated by IR camera measurements. When the surface temperature
was 360 K, the radiance temperatures of the multilayer multipeak selective
emitter were 314 and 309 K for the 3–5 and 8–12 μm
bands, respectively. Thermal management experiments demonstrated the
enhanced thermal stability of the multiresonance selective emitter,
especially in conditions of low pressure and high heat flux, when
compared to that of the low-emissivity film. This work provides a
practical strategy to enhance the thermal emission of a selective
emitter, expanding its potential beyond IR camouflage to various energy
applications.