Work

Correlating Mid‐Infrared Absorption With Radiative Efficiency in Passive Daytime Radiative Cooling Systems

Year: 2026

Type: article

Abstract: Passive daytime radiative coolers (PDRCs) are physical systems capable, on the Earth's surface, of achieving a net irradiation of energy toward outer space even under direct solar illumination. In order to achieve this amazing feat, PDRCs require tailored photonic properties all the way from the near-ultraviolet to the mid-infrared (mid-IR). In particular, PDRCs require high reflectivity over the solar-radiation range and selective absorbance (or equivalently emittance) in the mid-IR atmospheric transparency window. In this study we fabricated PDRCs composed of silica-loaded poly(4-methyl-1-pentene) thin films hot-pressed onto Ag-coated stainless-steel slabs, and we correlated the photonic response of these systems with their thermodynamic radiative efficiency. We clearly show that the presence of a strong emittance across the mid-IR range corresponds to a higher radiative power around room temperature, thereby establishing a clear quantitative criterion for PDRC assessment.

Source: Macromolecular Rapid Communications

DOI: 10.1002/marc.70329

Authors: Emma Spotorno, Paola Stagnaro, Lucia Conzatti, Simona Losio, Roberto Utzeri, Francesco Bisio

Institutions: University of Genoa, National Research Council, Istituto di Scienze e Tecnologie Chimiche "Giulio Natta", Superconducting and other Innovative Materials and Devices Institute

Language: English

Topic: Thermal Radiation and Cooling Technologies

Subfield: Civil and Structural Engineering

Field: Engineering

Domain: Physical Sciences

SDG: Affordable and clean energy

Open Access status: hybrid

Estimated APC paid: $4,550