A thermochromic material VO2-based metamaterial device for efficient temperature-adaptive radiative cooling

Abstract

Radiative cooling has attracted significant interest for its ability to passively dissipate heat into outer space without energy consumption. Despite its potential, challenges such as limited cooling power and complex fabrication processes persist. This study presents an efficient selective radiative cooling emitter enabled by a vanadium dioxide (VO₂) metamaterial. The device efficiently activates radiation cooling for heat dissipation at high temperatures, while deactivating cooling at low temperatures to avoid excessive cooling. Within the atmospheric window band, the average emissivity of the radiative cooling device increases significantly from 0.03 in low-temperature mode to 0.87 in high-temperature mode, while maintaining a nearly constant emissivity in the solar irradiation band. When the ambient temperature matches that of the radiative cooling metamaterial device, its cooling power reaches 277 W m⁻². Additionally, the design exhibits angular stability across varying incident angles and demonstrates scalability through systematic parameter optimization. The proposed temperature-adaptive radiative cooling metamaterial device holds promise for applications in adaptive optics systems, as well as in buildings and vehicles, offering significant potential for energy conservation and environmental protection.