A four-layer anti-reflection thin-film coating for flat-plate collector

Abstract

A spectrally selective antireflection optical thin-film coating to reduce the reflectance of glass cover of a solar flat-plate collector was designed and fabricated. The antireflection coating was applied on the incident surface of a 3 mm thick clear glass, commonly used in flat-plate collectors. The transmittance of solar radiation of ≈89% of clear glass increased to ≈92% on the entire visible light range of the spectrum. The design focused on the optical properties of glass and the interference of light waves to alter the optical characteristics of glass to a preferred value on a selected spectrum. Fabrication was done using thermal evaporation in high-vacuum coating system.