Wet chemical deposition of transparent conducting coatings made of redispersable crystalline ITO nanoparticles on glass and polymeric substrates

Abstract

Stable suspension made of fully redispersable In2O3:Sn (ITO) conducting nanoparticles were developed to obtain single thick transparent conducting films (up to 500nm) on different substrates using wet chemical deposition methods. The coatings can be processed at high sintering temperature process on glass substrates up to 1000°C to get electrical resistivity as low as 1.7x10(-3)Omega.cm and transmit more than 87% of the visible spectrum. The processing of transparent conductive coatings on polymeric (PC, PMMA, PVY, PE, PET, foils etc.) and glass substrates at low processing temperature was realized by using a modified ITO suspension in which a polymerisable inorganic-organic binder was added. The coatings can be cured by UV-irradiation and / Or by a low temperature heat treatment (T < 130°C) in air or reducing atmosphere. The electrical, optical, textural, mechanical and surface properties of the coatings are reported. Transparent conducting coatings with a single 570 nm thick layer exhibiting stable electrical resistivity of 9.2x10(-2) Omega.cm have been made by spin and dip coating process. A high transmission of about 87% is observed in the visible range. The adhesion and the abrasion resistance of the coatings pass the DIN or ASTMD tests: DIN58196-K2, ASTMD 3359, DIN 53151-Gt0, DIN 58196-G10 and DIN 58196-H25 and the hardness measured using the Pencil test ASTM D 3363-92a is 1H. UV-irradiation through a mask allows th easily pattern the coatings.