Stainless steel/tin/glass coating as spectrally selective material for passive radiative cooling applications

Glass substrates coated with a stainless steel–tin double layer were prepared in order to achieve the inverse greenhouse effect. The measurements of the optical properties of the samples indicate that the needed specific spectral selectivity is available. Practical tests of radiative cooling were performed during clear night using a blackbody radiator covered by the coated plate with glass facing the sky. The blackbody temperature was observed to be 6.0 °C below that of the ambient, and the cooling power was estimated to be 27.9 W/m2. Diurnal measurements indicated that cooling of the blackbody radiator is achieved except for approximately 6 hours around noon.