Transparent self-cleaning and antifogging silica nanoparticle films

• Superhydrophilic surfaces were produced by dip coating of silica nanoparticle films.
• Superhydrophilicity leads to surface antifogging and self-cleaning properties.
• Coated samples removed 86% more contaminants than bare glass when lightly rinsed.
• Solar transmittance of coated glass over 350–1100 nm wavelengths increased 4.3%.
• The silica nanoparticle films reflect less light than bare glass.

Self-cleaning and antifogging coatings are of great interest for application in outdoor solar cell installations to mitigate the performance loss and associated maintenance costs due to environmental contamination. These coatings, applied to the cover glass of solar panels, can remove contaminants when wetted with rain water and transmit more sunlight in foggy weather. Herein, we report a superhydrophilic silica nanoparticle film that exhibits the self-cleaning effect without relying on photocatalytic materials. When wetted with simulated light raining conditions, the coated glass removed 90% of surface contaminants, compared to only 48% removed from the bare glass. The deposited film created an antifogging surface in addition to increasing the solar transmittance (AM 1.5) of glass substrates by 4.3% over bare glass in the wavelength range of 350–1100 nm.