Photonic-Structure Colored Radiative Coolers for Daytime Subambient Cooling

Abstract

Daytime subambient radiative cooling provides a powerful strategy for realizing sustainable thermal management without any external energy consumption. However, in practical situations a dazzling white or silver appearance is undesirable for aesthetic and functional reasons. Therefore, developing colored radiative cooling materials is greatly significant for more potential applications but remains a big challenge so far. Here, we reported a flexible colored radiative cooler based on interferometric retroreflection-induced structural color, which resolves the conflict between a colorful appearance for aesthetics and high solar reflection for cooling. All colored radiative coolers achieve subambient cooling of 4 K even under sunshine stronger than 1000 W/m², while the same color commercial paints are 9-27 K higher than the ambient. Such a flexible, scalable, and low cost colored radiative cooler is expected to replace commercial paint in a practical scenario with aesthetic and cooling requirements, enabling substantial reduction in carbon emission and energy consumption.