High-Performance Indium-Tin Oxide (ITO) Electrode Enabled by a Counteranion-Free Metal-Polymer Complex

Although multicomponent inorganic thin films (metaloxides, -carbides, -nitrides, and -chalcogenides) have been synthesized by polymer-assisted deposition (PAD), synthesis of high-performance transparent conducting oxides (TCOs) has been rarely reported. TCO requires (i) removal of impurities, (ii) high-density oxide film, (iii) homogeneity in crystal structures and film morphology, and (iv) controllable elemental doping. This study performs a systematic investigation on preparation of stable multicomponent metal-polymer complex solutions by removing the counteranions in the solution. This study also proposes accurate acid-base titration for each metal species in order to minimize the amount of PEI, thus maximizing the density of the film. As a representative TCO, Sn-doped In-2 Omega(3) (ITO) films have been achieved. The ITO film has an excellent sheet resistance (24.5 Omega/sq) at 93% optical transparency, with a figure of merit of 2.1 x 10(-2) Omega(-1), which is comparable to the best.

Automated summary

This study achieved the preparation of high-performance transparent conducting oxides (TCOs) through the removal of counteranions in the solution and accurate acid-base titration, with Sn-doped In-2 Omega(3) (ITO) film being the most representative.