Evaluating the efficiency of utilizing selectively optimized metamaterial nanostructures for passive radiative cooling of satellites and components

Abstract

The need for efficient, smart radiators and thermal control technologies will be imperative to ensure the longevity of satellites and for carrying out temperature sensitive operations in space. Advancement in nanofabrication techniques has brought about the ability to create metamaterial nanostructures and selectively control their optical properties so that they reflect better in the visible spectrum and strongly emit in the infrared spectrum, which allows for better cooling. This meta-analysis looks at contemporary research that has utilised metamaterial nanostructures for passive radiative cooling attempting to identify the cooling trends among these structures. The absorbance, emissivity and reflection spectra of these structures are compared, and their effectiveness compared to conventional coolant coatings is critiqued upon. The defining thermodynamic parameters for this study were radiative cooling power and temperature reduction. Through inductive reasoning, we predict that the emissivity in the infrared of a pyramidal layered structure of Al2O3, TiO2 and SiO2 can outperform current material choices. Improving efficiency with the prediction outlined can provide increased radiative cooling. Keywords: Passive radiative cooling; thermal radiation; metamaterials; broadband optical filters; selective absorption and emission; two-dimensional thin film coatings; nanophotonic structures