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

• Published in: Journal of Coatings Technology and Research 2010, Vol.7 (2), p.261-269
• Main Authors: Königer, Tobias, Rechtenwald, Thomas, Al-Naimi, Ihab, Frick, Thomas, Schmidt, Michael, Münstedt, Helmut
• Format: Article
• Language: English
• Subjects: Chemistry and Materials Science; Corrosion and Coatings; Industrial Chemistry/Chemical Engineering; Materials Science; Polymer Sciences; Surfaces and Interfaces; Thin Films; Tribology
• ISSN: 1547-0091; 1935-3804
• DOI: 10.1007/s11998-009-9181-5

A CO 2 -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 CO 2 -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 CO 2 -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 CO 2 -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, CO 2 -laser-treated ITO nanoparticle coatings show a significant higher stability under oscillatory bending.