Effects of annealing and plasma treatment on the electrical and optical properties of spin-coated ITZO films

• The resistivity of ITZO was enhanced by H2 gas plasma treatment.
• The transmittance of H2 treated film was same as that of ref. after wet treatment.
• The plasma process was carried out at room temperature.

This paper reports the effects on the optical and electrical properties of indium tin zinc oxide (ITZO) films by annealing and hydrogen plasma treatment. ITZO films were prepared by spin-coating using ITZO nanoink. The sheet resistance of the spin-coated ITZO was decreased to 155 Ω/square after annealing at 300 °C. Subsequent inductively-coupled hydrogen plasma decreased the sheet resistance of the ITZO film further to 88 Ω/square due to the formation of a high density of O–H bonds and oxygen vacancies leaving a metal cluster on the surface, which is comparable to that of solution-processed ITO films. Although the transmittance of the hydrogen plasma-treated sample was decreased considerable by the formation of metal clusters, the transmittance and optical band gap could be enhanced without a deteriorating the electrical properties by removing the metal clusters using a H2SO4 solution.