A two-dimensional thin film structure with spectral selective emission capability suitable for high-temperature environments

• Published in: Case studies in thermal engineering Vol. 63; p. 105261
• Main Authors: Li, Xinkai, Liu, Yufang, Yu, Kun, Qian, Mengdan
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01-11-2024; Elsevier
• Subjects: Infrared stealth; Multilayer film; Radiation cooling; Spectral selective emission materials; Infrared stealth; Spectral selective emission materials; Multilayer film; Radiation cooling
• ISSN: 2214-157X; 2214-157X
• DOI: 10.1016/j.csite.2024.105261

Spectral selective emission materials, characterized by their high emission efficiency within specific wavelength ranges, play a crucial role in various fields such as infrared stealth and radiative cooling. In this study, leveraging the tunneling effect of ultrathin metal layers and the impedance matching principle, we designed a one-dimensional multilayer thin film structure composed of Mo/Ge/Al. This design successfully achieved spectral selective emission within the 3–14 μm infrared spectrum range, showcasing superior high-temperature infrared stealth capabilities. Research findings indicate that the infrared atmospheric window (ε3–5 μm = 0.40, ε8–14 μm = 0.30) maintains a low emissivity within the temperature range from room temperature to 400 °C, while high emissivity in non-infrared atmospheric windows (ε5–8 μm = 0.81) enables radiative cooling. The use of high emissivity in the non-infrared atmospheric window reduced the surface temperature of this structure by 15.3 °C compared to untreated Si substrate under similar heating conditions. The temperature reduction was 34.1 °C when compared to a Si substrate coated with a 200 nm Al film. This straightforward and easily scalable structure not only presents novel solutions for applications in infrared stealth and radiative cooling but also holds vast potential for diverse fields including military, aerospace, and industrial manufacturing, injecting fresh impetus and possibilities into technological advancement.