Colored temperature-adaptive radiative coating for all-season building thermal regulation

Energy-saving technologies for future buildings are increasingly emphasizing visual integration, making it crucial to achieve high efficiency without compromising aesthetic quality. While current research has been largely confined to optimizing thermal management efficiency, the synergistic integration of dynamic thermal regulation and aesthetic color tunability remains a significant and largely untapped frontier. To address this gap, we designed a colored temperature-adaptive radiative coating (CTRC) composed of ZnS, Ge, VO2, HfO2, and Al. The significant refractive index contrast between Ge and ZnS induces optical interference effects, enabling the modulation of structural colors over a wide range, from blue-violet to beige. Moreover, the CTRC maintains robust color stability at incident angles up to 60°, thereby preserving visual comfort. Notably, Within the Atmospheric window (8-13 μm), CTRC exhibits a remarkable transition from 0.07 at low temperatures to 0.97 at high temperatures based on the metal-insulator transition of VO2 combined with the superior impedance matching provided by the top Ge and ZnS layers. Simulation results further confirm outstanding HVAC energy-saving performance, with annual energy savings reaching 134 MJ/m2 in cold regions. Such performance highlights the strong potential of the CTRC for addressing thermal management issues in building applications.