Radiative cooling

Radiative cooling is the phenomenon where objects facing the sky spontaneously cool down below the ambient temperature, even under direct sunlight. Thermodynamically, a radiative cooler is in radiative thermal contact with three heat reservoirs: the sun, the atmosphere, and outer space. Fortunately, the wavelengths of interaction with all three are spectrally separated, which allows the engineering of the reflectance and emittance spectra of the radiative cooler to minimize radiative exchange with the sun and the atmosphere while maximizing thermal radiation towards outer space.

Our aim is to 1) determine theoretical limits on the cooling performance of radiative coolers, 2) design and test photonic nano/microstructures that allow control over an ultra-broadband spectral range spanning the UV, visible, near-IR (0.75~4 um), and mid-IR (4~20 um) wavelengths, and 3) develop efficient and effective algorithms for optimizing radiative cooling structures.

Figure 1. Radiative cooling schematic drawing

Selected Publications:

S. Jeon and J. Shin. Ideal spectral emissivity for radiative cooling of earthbound objects. Sci. Rep. 10, 13038 (2020).

S. Jeon and J. Shin. Directional radiation for optimal radiative cooling. Opt. Express. 29, 8376-8386 (2021).

S. Min, S. Jeon, K. Yun, and J. Shin. All-Color Sub-ambient Radiative Cooling Based on Photoluminescence. ACS Photonics. 9, 1196-1205 (2022).

S. Jeon, S. Son, S. Min, H. Park, H. Lee, and J. Shin. Daylong Sub-Ambient Radiative Cooling with Full-Color Exterior Based on Thermal Radiation and Solar Decoupling. 11, 2202129 (2023).