Hydrophobic and Environment-resistant Properties of SiO2/TiO2/SiO2-TiO2 Multilayer Antireflective Films at Wide Solar Spectra Range

In the help of coatings optimization design using TFCcal program, wide spectrum antireflective SiO2/TiO2/SiO2-TiO2 multilayer films with thickness precisely controlled were prepared on low iron glass using sol gel process and Czochralski method. The thickness of above layers were separately set as 80.9 nm (SiO2-TiO2, inner layer), 125.0 nm (TiO2, inter-layer) and 95.5 nm (SiO2, outer layer) according to the results of calculation. A high transmission and highly hydrophobic film was prepared by Czochralski method combined with methyl triethoxysilane (MTES) SiO2 modified base-catalyzed sol. The average optical transmittance could reach 97.03% in the wavelength range of 400-700 nm. After annealing treatment, the surface water contact angles were almost around 131.5 degrees. Furthermore, the optical transmittance only reduced 0.143% after aging for two months, showing that the prepared SiO2/TiO2/SiO2-TiO2 multilayer antireflective films had excellent hydrophobic and environment resistant properties.