Hydro-oleophobic silica antireflective films with high laser-damage threshold

A simple method of preparing hydro-oleophobic anitreflective films with high laser-damage threshold is reported in this article. By adding fluoroalkylsilanes (FAS) into reactant mixture as a co-precursor, FAS modified SiO(2) was obtained under base catalyzed hydrolysis and condensation of tetraethoxysilane The dip-coating films were deposited on two sides of fused silica substrates. The experimental results on the effect of adding fluoroalkylsilanes (FAS) as a co-precursor on the hydro-oleophobicity and optical properties of tetraethoxysilane (TEOS) based silica AR films, are reported. The hydro-oleophobicity of the films was tested by the contact angle measurements and the highest water contact angle of 136 degrees and oil (peanut) contact angle of 93 were obtained The surface chemical modification of the hydro-oleophobic films was confirmed using Fourier transform infrared spectroscopy (FTIR). For the films based on FAS and TEOS, additional absorption bands at 1100 cm(-1) corresponding to C-F bond presented, clearly indicating the organic modification of the films The highest optical transmittance of the hydro-oleophobic films was found to be 99.5%. By a Nd.YAG lasers the laser-damage threshold of as-deposited films was measured at 351 tun wavelength (1 ns). The laser-damage threshold was as high as 22.6 J/cm(2). Crown Copyright (C) 2010 Published by Elsevier Ltd All rights reserved.