Enhanced electrical conductivity of indium tin oxide films by Ag addition

Ag-added indium-tin-oxide (ITO) films were prepared using conventional radio frequency (rf) magnetron sputtering with an ITO target on which Ag chips were placed. A small amount of Ag addition (< 1 at.%) lowered the resistivity by similar to 30% with only a slight decrease in the visible range transparency. The enhancement in conductivity was equivalent to lowering the substrate temperature by similar to 50 degrees C. At a substrate temperature of 250 degrees C, the resistivity (rho) of 2.0 x 10(-4) Omega cm with a carrier density (n) of 7.1 x 10(20) cm(-3) and Hall mobility (mu) of 44 cm(2)V(-1)s(-1) was obtained for the ITO (8.1 at.% Sn) film with 0.6 at.% Ag, whereas rho = 2.8 x 10(-4) Omega cm with n = 4.9 x 10(20) cm(-3) and mu = 46 cm(2)V(-1)s(-1) was obtained for the ITO film without Ag addition. The Ag addition enhanced the crystallinity and the densification of the film. The enhanced electrical conductivity due to Ag addition is explained by the increase in the efficiency of Sn doping.