VO2-based active tunable emittance thermochromic flexible coatings

N Numan; B Mabakachaba; A Simo; Z Nuru; M Maaza

doi:10.1364/JOSAA.395647

VO₂-based active tunable emittance thermochromic flexible coatings

J Opt Soc Am A Opt Image Sci Vis. 2020 Nov 1;37(11):C45-C49. doi: 10.1364/JOSAA.395647.

Authors

N Numan, B Mabakachaba, A Simo, Z Nuru, M Maaza

PMID: 33175730
DOI: 10.1364/JOSAA.395647

Abstract

This contribution reports, for what we believe is the first time, on VO₂-based thin-film coatings on flexible Al substrates exhibiting a tunable positive emittance-switching Δε=(ε_H-ε_L)>0. More precisely, a layered stack of a-Si:H/SiO₂/VO₂ on flexible Al sheets presents minimum and maximum values of emissivity of about 0.18 and 0.57 at 40ºC and 83ºC, respectively, and hence allows an emittance-switching Δε of 0.39 and a relative variation Δε/ε_Λ of ∼217%. Such variations fit with the potential applications of such coatings as smart radiation devices in small satellites and spacecraft.