Microstructured surfaces for colored and non-colored sky radiative cooling.

Area of Science:

• Materials Science
• Optics
• Nanotechnology

Background:

• Passive radiative cooling offers a sustainable alternative for thermal management.
• Optimizing material properties is crucial for efficient radiative cooling performance.
• Achieving both cooling and aesthetic coloration presents a design challenge.

Purpose of the Study:

• To propose and analyze a novel structure for passive sky radiative cooling.
• To investigate the role of surface texturation and resonant absorption in optical properties.
• To explore the potential for tunable coloration in radiative cooling devices.

Main Methods:

• Electromagnetic simulations were employed to model the optical properties of the proposed structure.
• The structure consists of a surface-textured silica layer on a silver substrate.
• Thin transparent layers were integrated to achieve resonant absorption and coloration.

Main Results:

• The silica-on-silver structure exhibits near-ideal optical properties for radiative cooling.
• Surface texturation is essential for achieving high infrared emissivity.
• Resonant absorption within thin layers enables coloration without significantly compromising cooling power.
• Multiple resonators expand the achievable color palette.

Conclusions:

• The proposed simple structure demonstrates high potential for efficient passive radiative cooling.
• Surface texturation and resonant absorption are key design elements for performance and aesthetics.
• This approach offers a pathway towards multifunctional radiative cooling materials with tunable colors.