Figure 1C shows ideal spectral reflectivity of broadband and selective radiative cooling surface in the UV-Vis-NIR and MIR region Even though they have different behaviors in the whole mid-infrared re

This new surface demonstrates a low emissivity in the MIR region, which reduces the heat exchange between the radiative cooling surface and the cold source, thus extending the life of the cold source. The spectral reflectivity of the new surface shows a high absorptivity/emissivity in the atmospheric window, ensuring a sub-ambient temperature for effective preservation. This new surface can be applied to various low-temperature cold source preservation applications, such as in the medical and food industries.