Anti-reflection OTS-treated SiO₂ thin films with super-hydrophobic property

Synthesizing multifunctional films to apply to the glasses for optical and advanced engineering applications, especially for concentrating solar power application, is a severe challenge. Herein, we report an anti-reflection SiO₂ thin films with super-hydrophobic property. The SiO₂ thin films are successfully synthesized on the soda lime glass by sol-gel spin-coating method, using tetraethylorthosilicate as a precursor and octadecyltrichlorosilane as a modification agent. The properties of films were characterized by fourier transform infrared spectra, field emission scanning electron microscopy, UV–VIS–NIR spectrophotometer and water contact angles apparatus. The results indicate that anti-reflection SiO₂ thin films have excellent visible light transmittance ranging from 97.8 to 103.4% with treatment time in tetraethylorthosilicate solution increasing from 1 min to 3 h. Moreover, such film exhibits super-hydrophobic property with water contact angles of 150.6° when treatment time is 3 h, owning to a hierarchical structure of the SiO₂ nanoparticles (~50 nm) and microscale dendritic aggregates. Fortunately, anti-reflection octadecyltrichlorosilane-treated SiO₂ films with super-hydrophobic property display a promising application in various fields, especially in concentrating solar power for reducing specular reflectance efficiency.