Sol-gel derived antireflective coating with controlled thickness and reflective index

Optical properties and structure of antireflective coatings (AR) deposited from hydrolysed TEOS sol have been characterized in detail. The influence of various parameters on the formation of colloidal silica antireflective coatings by the dip-coating technique has been investigated. For the characterization of colloidal silica films, the UV-visible spectroscopy, laser ellipsometry, and atomic force microscopy were used. Using optimal sol-gel processing conditions (dipping rate - 40 mm/min, coating time - 20 s, and temperature - 20 oC), the colloidal silica coatings were obtained and characterized in comparison with non-coated glass substrate. The reflectance of AR coatings increased with increasing the temperature of sol-gel processing. The laser damage threshold of as deposited films was measured at 1064 nm (1H) and 335 nm (3H) wavelength using a Nd:YAG lasers. The laser damage threshold of AR coating exceeded 15.22 J/cm2 at 1064 nm and 26.82 J/cm2 at 355nm.