Photon‐Engineered All‐Day Radiative Warming Utilizing Solar and Atmospheric Energy

Abstract Maintaining optimal temperatures continuously is crucial for various applications, yet existing methods relying on selective solar absorbers fail to provide continuous warmth throughout the entire day. A photon‐engineered flexible film is proposed for all‐day radiative warming, integrating multiple functional layers to regulate radiation across different spectral bands. This design enhances the heat absorption efficiency of solar and atmospheric energy (α 0.3−2.5 µm = 0.95, α 5−8 µm = 0.75, α 14−16 µm = 0.84) while minimizing outward radiation (ɛ 8‐14 µm = 0.13). Experimental validation demonstrates superior performance over traditional low‐emissivity warming blankets under varying environmental conditions, achieving 9.4 °C higher temperature during the day and 1.4 °C higher at night. Moreover, the film's remarkable warming capability highlights its significant application value in anti‐condensation. This underscores its potential as a sustainable and effective thermal management solution for carbon neutrality.