Antifogging and antireflective silica film and its application on solar modules

Superhydrophilic silica film with antifogging and antireflective properties was prepared by dip-coating the glass in SiO2 nanoparticles sol. The transparent superhydrophilic film was composed of silica nanoparticles of about 20–30 nm in diameter. The combination of hydrophilic SiOH on the surface and nanoporous surface topography was believed to be responsible for the antifogging property. The nanopores also effectively reduced the refractive index of the film and resulted in the antireflective property. By sintering the multifunctional silica film, a pencil hardness of 2H could be obtained. Application of the functional film in full-sized photovoltaic modules (1580 × 808 × 35 mm) demonstrated an increase of the power output of about 2%, 5% and 8%, respectively, at incidence angles of 0°, 30° and 60°.