All-solution-processed, transparent thin-film transistors based on metal oxides and single-walled carbon nanotubes

Abstract

The fabrication of fully transparent thin-film transistor (TFT) arrays composed of metal oxides and SWCNTs was performed on a glass substrate through simple all-solution-processed, vacuum-free routes followed by thermal annealing treatments at 350 °C which is the lowest processing temperature reported to date. We adopted fluorine-doped indium tin oxide (ITO:F), stacked zirconium oxide/aluminium oxide/zirconium oxide (ZAZ), indium zinc oxide (IZO), and single-walled carbon nanotubes (SWCNTs) for gate electrodes, gate insulators, channel layers, and source/drain electrodes, respectively, which enabled the fabrication of TFT with desired-performance at a sufficiently low annealing temperature of 350 °C that is compatible with polymer substrates. The TFT fabricated with a back-gated SWCNT/IZO/ZAZ/ITO:F structure was highly transparent with a transmittance of 76.5% in the visible range and exhibited a mobility of 0.45 cm² V⁻¹ s⁻¹ and an on/off current ratio of ∼10⁶, which are comparable to those of hydrogenated amorphous silicon TFTs. These results suggest that all-solution-processed TFTs have the potential for lost-cost, fully transparent, flexible device applications.