Transparent conducting coatings made from redispersable crystalline nanoscaled powders

A new wet chemical concept is presented for the preparation of electrically conducting SnO2:Sb (ATO) and In2O3:Sn (ITO) coatings. It is based on the deposition by spin, dip or spray techniques of a solution containing crystalline nanoscaled particles fully redispersable in a solvent. The particle synthesis is carried out in a solution at temperatures 8 (for ATO) with solid contents up to 8.8 vol. %. Single layers with thickness up to 200 nm (ATO) and 400 nm (ITO) have been fabricated. Their sheet resistance decrease with the sintering temperature. Typical lowest values are 430 Ω□ (550 °C) for ATO and 90 Ω□ (900 °C) for reduced ITO. The resistivity of as fired ATO and ITO coatings is stable but it slightly increases with time for ITO in the reduced state. All coatings have a transmission in the visible range of about 90 %. Anti-glare conducting coatings on glass with 70 GU as well as antistatic coatings (R□ ≈ 1 MΩ□) on polycarbonate substrates have been obtained with chemically modified ITO suspensions.