Abstract
Silicon suboxide (SiOx) could be a potential material for radiative cooling due to appropriate infra-red absorption at wave-length (λ) between 8 and 13 μm. In this study, SiOx films ranging from x=0.98 to 1.7 were prepared by magnetron sputtering using a SiO sintered body target. An SiO0.98 single layer film had a relatively sharp absorption peak at λ=10 μm. The obtained SiO0.98 film showed amorphous and a black-brown color. An optical band gap (Eg) of the SiO0.98 film was 3.6 eV, and the SiOx (x>1.4) film was transparent in the UV-visible range with a wide optical band gap (>4 eV). A functionally graded SiOx layers showed broader absorption from λ=8 to 13 μm, promising for radiative cooling.
