Low-Temperature, High-Performance, Solution-Processed Indium Oxide Thin-Film Transistors

Abstract

Solution-processed In₂O₃ thin-film transistors (TFTs) were fabricated by a spin-coating process using a metal halide precursor, InCl₃, dissolved in acetonitrile. A thin and uniform film can be controlled and formed by adding ethylene glycol. The synthesized In₂O₃ thin films were annealed at various temperatures ranging from 200 to 600 °C in air or in an O₂/O₃ atmospheric environment. The TFTs annealed at 500 °C under air exhibited a high field-effect mobility of 55.26 cm² V⁻¹ s⁻¹ and an I_on/I_off current ratio of 10⁷. In₂O₃ TFTs annealed under an O₂/O₃ atmosphere at temperatures from 200 to 300 °C exhibited excellent n-type transistor behaviors with field-effect mobilities of 0.85−22.14 cm² V⁻¹ s⁻¹ and I_on/I_off ratios of 10⁵−10⁶. The annealing atmosphere of O₂/O₃ elevates solution-processed In₂O₃ TFTs to higher performance at lower processing temperature.