Journal of Coatings Technology and Research

, Volume 7, Issue 2, pp 261–269 | Cite as

CO2-laser treatment of indium tin oxide nanoparticle coatings on flexible polyethyleneterephthalate substrates

  • Tobias KönigerEmail author
  • Thomas Rechtenwald
  • Ihab Al-Naimi
  • Thomas Frick
  • Michael Schmidt
  • Helmut Münstedt


A CO2-laser treatment was used to improve the electrical conductivity of coatings of indium tin oxide (ITO) nanoparticles on flexible polyethyleneterephthalate (PET) substrates. The electrical conductivity and the transparency of CO2-laser-treated ITO nanoparticle coatings were characterized with regard to the application as transparent electrodes. Furthermore, the stability of the electrical conductivity under oscillatory bending was investigated. A specific resistance of 0.12 Ω cm is obtained by CO2-laser treatment without thermally damaging the PET film. The improvement of the electrical conductivity can be explained by a slight sinter neck formation. For a film thickness of 3 μm, a sheet resistance of 400 Ω/□ and a transmission in the visible range of 80% were achieved. The stability of the electrical conductivity of CO2-laser-treated ITO nanoparticle coatings under bending was investigated using a specially constructed device for the application of various oscillatory bending loads. For a bending radius of 10 mm, the sheet resistance does not exceed 1000 Ω/□ after 300 bending cycles. Compared to commercial sputtered ITO coatings, CO2-laser-treated ITO nanoparticle coatings show a significant higher stability under oscillatory bending.


Indium tin oxide (ITO) Nanoparticles Laser treatment Oscillatory bending tests 



The authors thank the German Research Foundation for their financial support, Evonik Degussa GmbH for providing the ITO nanoparticle dispersion, and Mitsubishi Polyester Films company for providing the PET films.


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Copyright information

© FSCT and OCCA 2009

Authors and Affiliations

  • Tobias Königer
    • 1
    Email author
  • Thomas Rechtenwald
    • 2
  • Ihab Al-Naimi
    • 1
  • Thomas Frick
    • 2
  • Michael Schmidt
    • 2
  • Helmut Münstedt
    • 1
  1. 1.Institute of Polymer MaterialsErlangenGermany
  2. 2.Bayerisches Laserzentrum GmbHErlangenGermany

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