Dispersion and microwave processing of nano-sized ITO powder for the fabrication of transparent conductive oxides

• Published in: Ceramics international 2016-12, Vol.42 (16), p.18296-18302
• Main Authors: Ghanizadeh, S., Peiris, T.A. Nirmal, Jayathilake, D.S.Y., Hutt, D.A., Wijayantha, K.G.U., Southee, D.J., Conway, P.P., Marchand, P., Darr, J.A., Parkin, I.P., Carmalt, C.J.
• Format: Article
• Language: English
• Subjects: Dispersants/Dispersion; Indium/Indium compounds; Nanoparticles; Thin films; Transparent conducting oxides
• ISSN: 0272-8842; 1873-3956
• DOI: 10.1016/j.ceramint.2016.08.157

Aqueous dispersions of tin-doped indium oxide (ITO) nanopowder were prepared and the effect of the addition of PEG 400, Tween 80 and β-alanine as dispersants was investigated using zeta potential and particle size distribution measurements. Both PEG 400 and β-alanine were found to produce stable dispersions that were used to deposit ITO thin films on glass substrates by dip and spin coating methods. The ITO thin films were heat-treated using both conventional and microwave heat treatment in order to improve the inter-particle connections and hence the resistivity and transparency of the films. All the films exhibited an average transmittance of >80% over the visible spectrum after being subjected to the heat treatment process. ITO films prepared with no dispersant showed very high resistivity values for both heating methods, however addition of 2wt% PEG 400 to the dispersion yielded a reduction in the resistivity values to 1.4×10−1Ωcm and 3.8×10−2Ωcm for conventionally and microwave treated films, respectively. The surface morphological studies confirmed that addition of dispersants improved the film uniformity and inter-particle connections of the ITO films considerably.