Design and Implementation of Three-Layer Mesoporous Silica Coating for Tri-wavelength Broadband Antireflection by Block Copolymer Assisted Sol–Gel Method

Abstract

A three-layer tri-wavelength broadband antireflective (AR) coating has been successfully fabricated on quartz substrate via a sol–gel route using acid-catalyzed silica sols. An ethylene oxide-propylene oxide-ethylene oxide triblock copolymer is used as a template to prepare ordered mesoporous SiO2 films. Assisted by Filmstar thin film design software, film thickness for each layer is optimized based on actual optical constants of the three mesoporous silica films. The three layers generate a reasonable refractive index gradient from the air, and thus the obtained AR coating possesses high transmittance of 99.24%, 99.66%, and 99.64% at 351 nm, 527 nm, and 1053 nm, respectively. The mesoporous SiO2 films with tough skeletons despite different porosity endow the coating with good abrasion-resistance, and 1H, 1H, 2H, 2H-Perfluorodecyltriethoxysilane is further used to modify the surface of the AR coating, which can improve the experimental stability of the coating. This work provides beneficial references for AR coating production of the sol–gel technique.