Passive Radiative Cooling Nanocomposite Film

The present invention is directed to a passive radiative cooling nanocomposite film, comprising a cyclic olefin copolymer (COC) base layer deposited on a substrate; one or more VO₂ layers, comprising VO₂ nanoparticles dispersed in a ketone-bearing solvent, deposited on the COC base layer, whereby the VO₂ nanoparticles dispersed in the one or more VO₂ layers percolate into the COC base layer; and a COC caping layer deposited on the one or more VO₂ layers. The passive radiative cooling nanocomposite film can further comprise two or more alternating VO₂ and intermediate COC layers sandwiched between the COC base layer and the COC caping layer, thereby providing a vertically stacked COC-VO₂– COC nanocomposite. The invention further provides methods to fabricate the passive radiative cooling nanocomposite films.