Oxide thin film transistors with ink-jet printed In-Ga-Zn oxide channel layer and ITO/IZO source/drain contacts

In-Ga-Zn oxide (IGZO) TFTs was fabricated by ink-jet printing technology on a silicon substrate with SiO₂ on top. The device fabrication process includes printing ITO electrodes and IGZO semiconductor layer. A typical printed TFT shows a mobility of 0.32 cm²/V s and a contact resistance of ~1 MΩ. Device performance was further improved by inserting an IZO layer between the source/drain electrode and IGZO channel, which results in a contact resistance of 0.05 MΩ, and an enhanced mobility of 0.82 cm²/V s.