Aerosol-based Deposition of Broadband Antireflective Silica Coating with Closed Mesoporous Structure

Solar energy will be a crucial part of the sustainable, fossil free energy production of the future. A majority of this will be produced by solar collectors and photovoltaics. Important for the efficient utilization of the incident solar energy for both technologies are a cover glass with antireflective coatings giving it a high solar transmittance. In the current paper we describe the development of antireflective mesoporous silica coatings on low-iron float glass using the aerosol-based nFOGTM deposition technique. The coatings exhibit a hexagonal and closed pore structure, high smoothness, superhydrophilic properties (contact angle <5 degrees) and consistent thicknesses of approximately 110 nm. This is in line with optimal thickness determined from simulations of the antireflective behavior. Low-iron float glass coated on both sides show a highly reproducible solar weighted transmittance of 95% in the wavelength range 300-2500 nm and an antireflective effect increasing with incident angle. The smoothness, closed pores and low contact angle indicate a high cleanability, which in combination with the high transmittance render a competitive broadband antireflective coating well adapted for solar glass applications.