The fast deposition of antireflection coating

In this investigation, the effect of deposition time (5, 60, or 300 s) on a double-sided antireflection (AR) coating done by layer-by-layer deposition of polyelectrolyte was determined. The different structures and transmittance of an AR coating induced by electric-field-assisted layer-by-layer deposition (ELBLD) (with voltage of 0.5, 5, 50, or 500 V) and normal deposition (with voltage of 0 V) were compared. The electric field was perpendicular to the glass surface. After 5.5 bilayers of PAH/PAA were fabricated, the film was exposed to an acidic treatment of HCl solution (pH 2.4) for 65 s, followed by a brief rinse (~15 s) in deionized water, blown dry with air, and heat treated at 220°C for 2 h. Regardless of whether the electric field was applied, the average transmittance of visible light of the AR coating was more than 96% except for the reduced transmittance because of the excessive deposition of polyelectrolyte at an applied voltage of 500 V and a deposition time of 300 s. Average transmittance of 97.68 ± 0.31% was obtained at normal deposition of 5.5 bilayers with deposition time of 60 s. The polyelectrolytes had a propensity to form larger particles or accumulate into bundles under ELBLD, which was detrimental to the transmittance of an AR coating. Therefore, at the same deposition time, transmittance values of ELBLD samples were slightly lower than those of normal deposition. In other words, in the overall performance, the AR films of normal deposition are superior to those of ELBLD. The blowing pressure applied to dry the coating had significant impact on the quality of the film.