Transparent conducting sol-gel ATO coatings for display applications by an improved dip coating technique

Abstract

Transparent conducting coatings of sol—gel ATO (antimony-doped tin oxide) were used to improve surface smoothness of commercial sputter-deposited ITO (indium tin oxide) coatings for application as display electrodes. In order to overcome the deteriorating evaporation-cooling during dip coating, the coating solution was heated moderately to 25 °C thus providing the substrate with the required heat. This way, the surface roughness of the ITO could be reduced with an only 45 nm thick ATO coating to Rpv = 3.8 nm (Ra = 0.4 nm) compared to 31 nm (3.8 nm) for the ITO substrate. Another benefit of such additional coating is the possibility to tailor surface properties of the electrodes in wide ranges. This was used to increase the work function of the ITO substrate from initially 4.3—4.6 eV to about 4.8—5.2 eV by the ATO coating.