Journal of Sol-Gel Science and Technology

, Volume 66, Issue 1, pp 120–125 | Cite as

Microstructure and performance of AZO thin films prepared by sol–gel processing

  • Rainer Jahn
  • Peer LöbmannEmail author
Original Paper


Al-doped zinc oxide (AZO) films were prepared by a wet-chemical coating technique, their microstructure and crystal growth were characterized as a function of the single layer thickness. When similar final thicknesses are attained by more multiple subsequent coating-firing cycles, film porosity is reduced from over 14 to 2 %. Simultaneously the AZO crystallite size is increased from approximately 23 to 60 nm, a preferential c-axis oriented growth is observed. Different substrates (soda-lime glass, soda-lime glass with a SiO2 barrier coating, borosilicate glass and alkali-free display glass) were used and the resulting AZO films were compared. It is found that the substrate composition primarily affects grain growth and subsequently the electrical performance of the AZO films.


Thin film AZO TCO Ellipsometric porosimetry Substrate 



The authors are indebted to Angelika Schmitt for the EP measurements. Hall measurements were performed at Fraunhofer IST in Braunschweig, Germany, by Christina Schulz.


  1. 1.
    Hüpkes J, Owen J, Pust S, Bunte E (2012) Chemical etching of zinc oxide for thin-film silicon solar cells. Chem Phys Chem 13:66–73CrossRefGoogle Scholar
  2. 2.
    Prodi-Schwab A, Lüthge T, Jahn R, Herbig B, Löbmann P (2008) Modified procedure for the sol–gel processing of indium-tin oxide (ITO) films. J Sol-Gel Sci Tech 47:68CrossRefGoogle Scholar
  3. 3.
    Goebbert C, Nonninger R, Aegerter M, Schmidt H (1999) Wet chemical deposition of ATO and ITO coatings using crystalline nanoparticles redispersable in solutions. Thin Solid Films 351:79CrossRefGoogle Scholar
  4. 4.
    Schuler T, Krajewski T, Grobelsek I, Aergerter M (2004) A microstructural zone model for the morphology of sol-gel coatings. J Sol-Gel Sci Technol 31:235CrossRefGoogle Scholar
  5. 5.
    Schuler T, Krajewski T, Grobelsek I, Aergerter M (2006) Influence of structure zone model parameters on the electrical properties of ZnO:Al sol–gel coatings. Thin Solid Films 502:67CrossRefGoogle Scholar
  6. 6.
    Wang C, Meinhardt J, Löbmann P (2010) J Sol-Gel Sci Technol 33:148CrossRefGoogle Scholar
  7. 7.
    Bittner A, Jahn R, Löbmann P (2011) TiO2 thin films on soda-lime and borosilicate glass prepared by sol–gel processing: influence of the substrates. J Sol-Gel Sci Technol 58:400–406CrossRefGoogle Scholar
  8. 8.
    Baklanov MR, Mogilnikov KP, Polovinkin VG, Dultsev FN (2000) Determination of pore size distribution in thin films by ellipsometric porosimetry. J Vac Sci Technol B 18(3):1385–1391CrossRefGoogle Scholar
  9. 9.
    Baklanov M, Green M, Maex K (2007) Dielectric films for advanced microelectronics. Wiley, West SussexCrossRefGoogle Scholar
  10. 10.
    Bittner A, Schmitt A, Jahn R, Löbmann P (2012) Characterization of stacked sol–gel films: comparison of results derived from scanning electron microscopy, UV–vis spectroscopy and ellipsometric porosimetry. Thin Solid Films 520:1880CrossRefGoogle Scholar
  11. 11.
    Löbmann P (2012) Transparent conducting oxides. In: Schneller T, Waser R, Kosec M, Payne D (eds) Chemical solution deposition of functional oxide thin films. SpringerGoogle Scholar
  12. 12.
    Bocko E (2008) Highly engineered glass substrates for LCD television: why reducing value is incompatible with consumer expectations. Inform Disp 24(5):26Google Scholar

Copyright information

© Springer Science+Business Media New York 2013

Authors and Affiliations

  1. 1.Fraunhofer-Institut für SilicatforschungWürzburgGermany

Personalised recommendations