A radiative cooler with thermal insulation ability

Designer SiO2 Metasurfaces for Efficient Passive Radiative Cooling

“…For example, soda-lime glass and borosilicate glass are two common types of glass that are made with SiO 2 as their principal component, but they differ in their composition of added minerals and impurities, which results in variations of the optical properties. While fused silica is highly reflective in the atmospheric window region (≈70%), the added impurities in soda [ 54] Experimental 7 --Zhang et al ( 2019) [ 55] Experimental ---Ishii et al (2020) [ 56] Experimental 5.9 0.85 -Zhao et al (2019) [ 36] Silica fibers Numerical --178 Yalçın R A et al (2020) [ 57] Experimental 6.0 0.90 112 Tsai et al (2023) [ 28] 1D gratings Numerical 31.4 --Zhu et al ( 2013) [ 58] Numerical --114 Blandre et al (2020) [ 59] Numerical -> 0.90 98 Liu et al ( 2021) [ 60] Experimental 3.6 0.91 -Zhao et al (2022) [ 61] 2D micropatterns Experimental 13 --Zhu et al (2015) [ 62] Experimental 2 -600 Long et al (2019) [ 63] Numerical 9 ≈1.0 121 Li et al (2022) [ 64] Experimental 7 0.952 -Pinto et al ( 2023) [ 52] Numerical 17.6 ≈1.0 -Zhu et al ( 2014) [ 45] Experimental -> 0.96 -Lu et al (2017) [ 65] Experimental 9.2 > 0.98 -Fathabadi et al ( 2021) [ 38] Experimental 3 0.977 -Akerboom et al (2022) [ 39] Experimental 7.1 0.95 143 Ding et al (2022) [ 37] Experimental -0.947 -Arrés Chillón et al (2022) [ 66] Microspheres Experimental -> 0.94 -Atiganyanun et al (2018) [ 67] Experimental ≈6.9 --Fan et al (2020) [ 68] Numerical 73 --Whitworth et al (2021) [ 53] Experimental 19 >0.98 350 Fernandez et al (2019) [ 40] Experimental 5 0.946 -Lin et al (2022) [ 69] Numerical -0.916 80 Chen et al (2021) [ 70] lime glass reduce the reflectance in the reststrahlen band resulting in a relatively lower reflectance in the desired region (≈30%), compared to that of pure fused-SiO 2 . Various photonic techniques also have been utilized to enhance th...…”

“…In 2018, Atiganyanun et al [67] showed that a coating made of densely packed SiO 2 microspheres could increase optical scattering in the solar spectrum and thermal emission in the atmospheric transparency window, surpassing commercially available cooling white paints in terms of daytime cooling. Fan et al [68] conducted an experiment mixing micro-and nanoscale SiO 2 spheres in different ratios, as schematically represented in Figure 8a. The SEM images corresponding to the 1:1 ratio are displayed in Figure 8b, reaching high emissivity within the atmospheric window due to the combined action of both nanoscale and micron-scale SiO 2 particles (Figure 8c).…”

“…Fan et al. [ 68 ] conducted an experiment mixing micro‐ and nanoscale SiO 2 spheres in different ratios, as schematically represented in Figure a. The SEM images corresponding to the 1:1 ratio are displayed in Figure 8b, reaching high emissivity within the atmospheric window due to the combined action of both nanoscale and micron‐scale SiO 2 particles (Figure 8c).…”

“…Reproduced with permission. [ 68 ] Copyright 2020, Elsevier. d) Numerical discretization of the spheres and shells, respectively, used in the rigorous coupled wave analysis calculations.…”

“…b) SEM images of the radiative coolers with a mixing mass ratio of 1:1. c) Fourier-transform infrared absorption spectrum of the nano-sized particles, micronized particles, and the cooler without PE substrate in the mid-infrared band. Reproduced with permission [68]. Copyright 2020, Elsevier.…”