High performance double layer hydrophobic antireflective coatings on glass prepared by sol–gel method

• Published in: Open ceramics 2024-06, Vol.18, p.100607, Article 100607
• Main Authors: Haritha, A.H., Faturíková, K., Duran, A., Galusek, D., Castro, Y., Velázquez, J.J.
• Format: Article
• Language: English
• Subjects: Antireflective hydrophobic coating; Contact angle; Silica-titania; Sol-gel; Solar cell
• ISSN: 2666-5395; 2666-5395
• DOI: 10.1016/j.oceram.2024.100607

A double layer coating was designed and fabricated on glass surfaces by sol-gel method using a silica-titania (SiO2–TiO2) thin film as the bottom layer and an inorganic-organic (triethoxy(octyl)silane (OTES) modified SiO2) upper layer. SiO2 and TiO2 sols were prepared using tetraethyl orthosilicate (TEOS) and titanium isopropoxide (TIP) as precursors and nitric acid (HNO3) as catalyst. The refractive index of the SiO2–TiO2 and OTES modified SiO2 layers were 1.79 and 1.45, and their thicknesses were approximately 76.8 nm and 94.2 nm, respectively. The results show an increase of 7% in transmittance respect to the uncoated glass substrate. At the same time, OTES-modified SiO2 top layer significantly improved the hydrophobicity of the system; the water contact angle of film increased from 56° for system without the OTES modified SiO2 layer to 102° for the system with OTES-modified SiO2 top layer. [Display omitted] •Successfully developed a double-layer antireflective hydrophobic coating on glass surfaces by solgel dip coating method.•A 7 % increase in transmittance compared to uncoated glass at 550 nmwavelength.•OTES modified SiO2 top layer significantly enhanced hydrophobicity of the glass substrate.•The double-layer AR coating maintained adhesion and high transmittance after two years of exposure to ambient conditions.•Highly transparent and hydrophobic double-layer coating is a reliable choice for a wide range of practical applications.