Synergistic solar spectrum and atmospheric window tunable VO ₂ /BaF ₂ photonic structure for all-season smart thermal management

Static radiative cooling faces the issue of overcooling in winter, leading to increased thermal load. Existing dynamic regulation efforts primarily focus on emissivity modulation, with room for improvement in the synergistic regulation of solar spectral reflectance. In this study, we have designed a VO₂/BaF₂ photonic structure that achieves synergistic dynamic regulation of emissivity in the atmospheric window and solar spectral reflectance. After optimizing the structural parameters using genetic algorithms, the structure achieved significant modulation amplitudes of 0.36 and 0.70 in the solar spectrum and atmospheric window. Theoretical calculations demonstrate angle insensitivity up to approximately 75° for the designed structure, and its physical mechanism is revealed through electric field distribution. Energy consumption analysis proves that this design is suitable for heating and cooling needs in buildings across different climatic zones, with maximum energy savings exceeding 60 MJ/m². Benefiting from the thermochromic properties of VO₂, the proposed structure enables temperature-adaptive, all-season smart thermal management in buildings, with significant application potential across diverse fields.