Optical characterization of anti reflective sol-gel coatings fabricated using dip coating method

In recent years, there has been a growing interest in further development of sol-gel method which can produce ceramics and glasses using chemical precursors at relative low-temperatures. The applications for sol-gel derived products are numerous. Department of General and Inorganic Chemistry with Laser Research Center of Vilnius University and Institute of Physics continues an ongoing research effort on the synthesis, deposition and characterization of porous solgel. Our target is highly optically resistant anti-reflective (AR) coatings for general optics and nonlinear optical crystals. In order to produce AR coatings a silica (SiO2) sol-gel has been dip coated on the set of fused silica substrates. The optical properties and structure of AR-coatings deposited from hydrolysed tetraethylorthosilicate (TEOS) sol were characterized in detail in this study. The influence of different parameters on the formation of colloidal silica antireflective coatings by dip-coating technique has been investigated. All samples were characterized performing, transmission electron microscopy, UV-visible spectroscopy, atomic force microscopy, ellipsometric, total scattering and laser-induced damage threshold measurements. Herewith we present our recent results on synthesis of sol-gel solvents, coating fabrication and characterization of their optical properties.

[1]  Michael T. Harris,et al.  Chemical reaction kinetics leading to the first Stober silica nanoparticles – NMR and SAXS investigation , 2003 .

[2]  Björn Karlsson,et al.  Antireflection of glazings for solar energy applications , 1998 .

[3]  Arne Roos,et al.  Antireflection treatment of low-emitting glazings for energy efficient windows with high visible transmittance , 2003 .

[4]  K. J. Cathro,et al.  Silica low-reflection coatings for collector covers, by a dip-coating process , 1984 .

[5]  Dunbar P. Birnie,et al.  Porosity and composition effects in sol-gel derived interference filters , 1995 .

[6]  P. Sujatha Devi,et al.  Porous anti-reflective silica coatings with a high spectral coverage by sol-gel spin coating technique , 2003 .

[7]  M. Z. Hu,et al.  Size, volume fraction, and nucleation of Stober silica nanoparticles. , 2003, Journal of colloid and interface science.

[8]  A. Melninkaitis,et al.  Automated test station for laser-induced damage threshold measurements according to ISO 11254-2 standard , 2006, SPIE LASE.

[9]  Yuhan Sun,et al.  Sol-gel broadband anti-reflective single-layer silica films with high laser damage threshold , 2003 .

[10]  Charles F. Zukoski,et al.  Studies of the kinetics of the precipitation of uniform silica particles through the hydrolysis and condensation of silicon alkoxides , 1991 .

[11]  L. Hench,et al.  The sol-gel process , 1990 .

[12]  Fernando Galembeck,et al.  Size Dependence of Stöber Silica Nanoparticle Microchemistry , 2003 .

[13]  G. C. Wall.  THE SOL-GEL PROCESS , 1965 .

[14]  I. Thomas,et al.  Method for the preparation of porous silica antireflection coatings varying in refractive index from 1.22 to 1.44. , 1992, Applied optics.

[15]  I. Thomas,et al.  High laser damage threshold porous silica antireflective coating. , 1986, Applied optics.

[16]  Atsushi Hozumi,et al.  The formation and growth mechanisms of silica thin film and spherical particles through the Stöber process , 2003 .

[17]  Björn Karlsson,et al.  Optical and mechanical properties of sol-gel antireflective films for solar energy applications , 1999 .

[18]  W. Stöber,et al.  Controlled growth of monodisperse silica spheres in the micron size range , 1968 .

[19]  Charles F. Zukoski,et al.  Preparation of monodisperse silica particles: control of size and mass fraction , 1988 .

[20]  Volker Wittwer,et al.  Subwavelength-structured antireflective surfaces on glass , 1999 .

[21]  V. Sirutkaitis,et al.  Absorptance and scattering losses measurements in IR range by high average power tunable radiation of optical parametric oscillator based on a periodically poled lithium niobate , 2006, SPIE LASE.