Fabrication of Sol-Gel derived Antireflective Thin Films of $SiO_2-ZrO_2$ System

솔-젤법에 의한 $SiO_2-ZrO_2$계 무반사 박막의 제조

  • Kim, Byong-Ho (Dept. of Materials Science and Eng., Korea University) ;
  • Hong, Kwon (Dept. of Materials Science and Eng., Korea University) ;
  • Namkung, Jang (Dept. of Materials Science and Eng., Korea University)
  • 김병호 (고려대학교 재료공학과) ;
  • 홍권 (고려대학교 재료공학과) ;
  • 남궁장 (고려대학교 재료공학과)
  • Published : 1995.05.01

Abstract

In order to reduce reflectance of soda-lime glass having average reflectance of 7.35% and refractive index of 1.53, single (SiO2), double (SiO2/20SiO2-80ZrO2), and triple (SiO2/ZrO2/75SiO2-25ZrO2) layers were designed and fabricated on the glass substrate by Sol-Gel method. Stble sols of SiO2-ZrO2 binary system for antireflective (AR) coatings were synthesized with tetraethyl orthosilicate (TEOS) and zirconium n-butoxide as precursors and ethylacetoacetate (EAcAc) as a chelating agent in an atmosphere environment. Films were deposited on soda-lime glass at the withdrawal rates of 3~11 cm/min using the prepared polymeric sols by dip-coating and they were heat-treated at 45$0^{\circ}C$ for 10 min to obtain homogeneous, amorphous and crack-free films. In case of SiO2-ZrO2 binary system, refractive index of film increased with an increase of ZrO2 mol%. Designed optical constant of films could be obtained through varying the withdrawal rate. In the visible region (380~780nm), reflectance was measured with UV/VIS/NIR Spectrophotometer. Average reflectances of the prepared single-layer [SiO2 (n=1.46, t=103nm)], double-layer [SiO2 (n=1.46, t=1-4nm)/20SiO2-80ZrO2 (n=1.81, t=82nm)], and triple-layer [SiO2 (n=1.46, t=104nm)/ZrO2 (n=1.90, t=80nm)/75SiO2-25ZrO2 (n=1.61, t=94 nm)] were 4.74%, 0.75% and 0.38%, respectively.

Keywords

References

  1. Solar Energy v.32 Silica Low-Reflection Coatings for Collector Covers by a Dip-Coating Process K. Cathro;D. Constable;T. Solaga
  2. Physics of Thin Films v.2 Antireflection Coatings for Optical and Infrared Optical Materials J.T. Cox;G. Hass;G. Hass(ed.);R.E. Thun(ed.)
  3. J. Am. Ceram. Soc. v.67 no.2 Development of Porous Antireflective Films on Soda-Lime-Silica Glass V.T. Rone(et al.)
  4. Ceram. Bull. v.58 no.11 Antireflection Films on Alkali-Borosilicate Glasses Produced by Chemical Treatments T.H. Elmer;F.W. Martin
  5. Applied Optics v.19 Investigation of Porous Oxides as an Antireflective Coating for Glass Surfaces B.E. Yoldas
  6. Applied Optics v.21 Gradient-index AR Film Deposited by the Sol-Gel Process S.P. Mukherjee;W.H. Lowdermilk
  7. Sol-Gel Technology for Thin Films, Fibers, Preforms, Electronics and Speciality Shapes Antireflective Films from Sol-Gel Process R.B. Pettit(et al.);L.C. Klein(ed.)
  8. Applied Optics v.26 Single-layer TiO₂ and Multilayer TiO₂SiO₂ Optical Coatings Prepared from Colloidal Suspensions I.M. Thomas
  9. Applied Optics v.18 Antireflective Coatings Applied From Metal-Organic Derived Liquid Precursors B.E. Yoldas;T.W. O'Keeffe
  10. Thin-Film Optical Filters Basic Theory H.A. Macleod
  11. Applied Optics v.17 no.4 Fast Computation Method for Derivatives of Multilayer Reflectance C.J. Laan;H.J. Frankena
  12. Introduction to Optics Theory of Multilayer Films F.L. Pedrotti;L.S. Pedrotti
  13. Sol-Gel Science C.J. Brinker;G.W. Scherer
  14. Ceramic Films and Coatings Optical Thin Films David G. Coult;J.B. Wachtman(ed.);R.A. Haber(ed.)