This paper reports the development of transparent radiative cooling metamaterials as cover windows for foldable and flexible electronic displays. These 50-micron-thick metamaterials, created by embedding optically modulating microstructures in clear polyimide, exhibit excellent light emission in the atmospheric window while maintaining optical transparency, mechanical robustness, and moisture impermeability. The metamaterials effectively mitigate temperature rise in heat-generating devices exposed to solar irradiance and enhance thermal management in dark conditions, significantly improving the light output performance of LEDs by suppressing thermalization-related deterioration.

Kang Won Lee, Jonghun Yi, Min Ku Kim, Dong Rip Kim