Radiative cooling is a passive cooling method which can lower the temperature without any energy consumption. Herein, we developed novel radiative cooing materials based on ceramic and polymeric metamaterials. They exhibit up to 90% absorption at broadband IR wavelengths (8-25 μm) and less than 5 % absorption at AM 1.5 solar spectrum, which provides the outstanding cooling ability of 2-4 K under sunlight exposure.

Herein, we developed ceramic and polymeric metamaterials performing daytime radiative cooling, spectral optimization, and near-zero energy consumption of cooling techniques. The  materials are cost-effective and could be rapidly fabricated by solution-based process for future massive production, which provides the outstanding cooling ability of 2-4 K under sunlight exposure.

In general, our radiative cooling materials could be utilized for green buildings, solar thermal power generation systems and low-grade heat dissipation from power stations. Also, radiative cooling materials might be integrated within a wide variety of existing and new building air conditioning systems.