Wet chemical deposition of ATO and ITO coatings using crystalline nanoparticles redispersable in solutions

Abstract

The deposition of SnO2:Sb (ATO) and In2O3:Sn (ITO) transparent conducting coatings on glass substrate has been demonstrated by many techniques such as CVD, sputtering, vacuum deposition and sol-gel process. This paper presents an alternative process for the deposition of such coatings at room temperature by spin, dip and spray coating techniques using solutions prepared with crystalline nanoparticles fully redispersed in water (for ATO, ITO) or alcohol (for ITO) with solid contents up to 10-15 Vol.%, respectively. The deposited green coatings have been sintered at temperature as high as 900 degrees C. In2O3:Sn coatings have a resistivity of 1.5 x 10(-2) Omega cm as sintered and 3.4 x 10(-3) Omega cm after annealing in nitrogen atmosphere, The resistivity of ATO single coatings shows a minimum rho = 1.7 x 10-2 Omega cm after annealing at 550 degrees C. SnO2:Sb coatings present long term stability but the resistivity of annealed ITO coatings steadily increases with time to a value three times higher. All coatings have a high optical quality with transmission in the visible range larger than 90%.