Open AccessMicrostructured surfaces for colored and non-colored sky radiative cooling
Author(s) -
Etienne Blandre,
Refet Ali Yalçın,
Karl Joulain,
Jérémie Drevillon
Publication year - 2020
Publication title -
optics express
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.394
H-Index - 271
ISSN - 1094-4087
DOI - 10.1364/oe.401368
Subject(s) - emissivity , materials science , optics , radiative cooling , low emissivity , infrared , radiative transfer , optoelectronics , colored , selective surface , substrate (aquarium) , absorption (acoustics) , physics , composite material , thermodynamics , oceanography , geology
We propose a simple structure for passive sky radiative cooling made of a surface-textured layer of silica on a silver substrate. Using electromagnetic simulations, we show that the optical properties of such structures are near-ideal, due to the large reflectivity of silver in the solar spectrum and the large emissivity of silica in the infrared. Surface texturation is key to obtain near-unity emissivity in the infrared. By using thin transparent layers sandwiched between silver layers at the bottom of the structures, resonant absorption can be obtained, leading to coloration while keeping acceptable radiative cooling power. Using multiple resonator increases the color palette that can be obtained.