RT Journal Article SR Electronic T1 High-performance subambient radiative cooling enabled by optically selective and thermally insulating polyethylene aerogel JF Science Advances JO Sci Adv FD American Association for the Advancement of Science SP eaat9480 DO 10.1126/sciadv.aat9480 VO 5 IS 10 A1 Leroy, A. A1 Bhatia, B. A1 Kelsall, C. C. A1 Castillejo-Cuberos, A. A1 Di Capua H., M. A1 Zhao, L. A1 Zhang, L. A1 Guzman, A. M. A1 Wang, E. N. YR 2019 UL http://advances.sciencemag.org/content/5/10/eaat9480.abstract AB Recent progress in passive radiative cooling technologies has substantially improved cooling performance under direct sunlight. Yet, experimental demonstrations of daytime radiative cooling still severely underperform in comparison with the theoretical potential due to considerable solar absorption and poor thermal insulation at the emitter. In this work, we developed polyethylene aerogel (PEA)—a solar-reflecting (92.2% solar weighted reflectance at 6 mm thick), infrared-transparent (79.9% transmittance between 8 and 13 μm at 6 mm thick), and low-thermal-conductivity (kPEA = 28 mW/mK) material that can be integrated with existing emitters to address these challenges. Using an experimental setup that includes the custom-fabricated PEA, we demonstrate a daytime ambient temperature cooling power of 96 W/m2 and passive cooling up to 13°C below ambient temperature around solar noon. This work could greatly improve the performance of existing passive radiative coolers for air conditioning and portable refrigeration applications.