Photonic-Structure Colored Radiative Coolers for Daytime\nSubambient Cooling

Abstract

Daytime\nsubambient radiative cooling provides a powerful strategy\nfor realizing sustainable thermal management without any external\nenergy consumption. However, in practical situations a dazzling white\nor silver appearance is undesirable for aesthetic and functional reasons.\nTherefore, developing colored radiative cooling materials is greatly\nsignificant for more potential applications but remains a big challenge\nso far. Here, we reported a flexible colored radiative cooler based\non interferometric retroreflection-induced structural color, which\nresolves the conflict between a colorful appearance for aesthetics\nand high solar reflection for cooling. All colored radiative coolers\nachieve subambient cooling of 4 K even under sunshine stronger than\n1000 W/m², while the same color commercial paints are 9–27\nK higher than the ambient. Such a flexible, scalable, and low cost\ncolored radiative cooler is expected to replace commercial paint in\na practical scenario with aesthetic and cooling requirements, enabling\nsubstantial reduction in carbon emission and energy consumption.