Study on the SiO₂ antireflective coatings prepared from sol-gel process

SiO₂ antireflective coatings were dip-coated by sol-gel method with TEOS as precursor and ammonia as catalyst. The influence of hydrolysis condition and ageing time on the performance of the SiO₂ coating was studied in detail. It's found that the peak value of transmission spectrum and antireflective wavelength was impervious to the increase of the NH₃/TEOS molar ratio, whereas its optimal time for coating was shortened; when the NH₃/TEOS molar ratio is between 0.9 and 1.05, the optimal time was less than a week. It s also found that the antireflective effect of the film was optimal while the reflective index of the sol is lowest, and the peak transmission of coatings are about 98%.