2604.01290 Radiative Cooling Below Ambient Temperature by 8.2 Kelvin During Daytime Using a Four-Layer Photonic Structure: Field Measurements Over 90 Days
We report a systematic investigation of radiative cooling with quantitative characterization spanning multiple length scales and operating regimes. Our methodology combines first-principles theoretical analysis, finite-element numerical simulations, and experimental measurements on fabricated samples to establish precise performance boundaries.