Thermally Induced Rapid, Scalable Fabrication of Structural-Colored Radiative Cooling Films with High Cooling Efficiency

Achieving high performance in passive daytime radiative cooling (PDRC) typically requires full reflection of visible light, which limits the color diversity of PDRC materials. Although the development of colored radiative cooling materials has attracted substantial interest, significant challenges remain in terms of large-scale fabrication, preservation of cooling performance, and long-term durability. This study presents a rapid and scalable strategy for fabricating colorful multilayer composite films with high cooling efficiency. A three-dimensional photonic crystal (3DPC) structural color layer was prepared via thermally controlled rapid dip-coating. Below this layer, hollow glass beads (HGBs) are integrated to induce multiple scattering of sunlight transmitted through the structural color layer, thereby enhancing reflectivity. Polydimethylsiloxane acts as the film-forming matrix, securing the 3DPC and HGBs structures, imparting mechanical and environmental stability, and providing high emissivity within the atmospheric transparency window (ATW). The colored films with an average solar reflectance of 96.1% and an ATW emissivity of 0.951 deliver a daytime cooling power of 95.62 W/m 2 . Field tests confirm consistent temperature reductions of approximately 10 °C in ventilated building environments and more than 17 °C in enclosed vehicle settings. Additionally, the films demons…