Drop-on-demand inkjet printing is
used to deposit indium
tin oxide
(ITO) transparent and conductive thin films. ITO printable ink is
prepared by dissolving indium hydroxide and tin (IV) chloride into
ethanol with the assistance of acetic acid/tert-butylamine
ionic liquid. Ionic liquid-assisted ITO ink exhibits a complete wetting
behavior on the glass substrate and a tunable viscosity, which makes
it particularly suitable for the inkjet printing fabrication of ITO
thin films. After annealing at 500 °C in forming gas, ITO thin
films with a sheet resistance of 99 Ω/□, a resistivity
of 2.28 × 10–3 Ω·cm,
and a transmittance of 95.2% in the range of 400–1000 nm can
be obtained. The effects of annealing temperature on the resistivity,
mobility, carrier concentration, transmittance, and optical band gap
are investigated systematically. Compared with commercial ITO thin
films made by conventional vacuum-based deposition approaches, these
printable ITO thin films have a higher material utilization.