Electrohydrodynamic Jet-Printed Zinc–Tin Oxide TFTs and Their Bias Stability

Zinc-tin oxide (ZTO) thin-film transistors (TFTs) were fabricated using an electrohydrodynamic-jet (EHD-jet) printing technique at annealing temperatures ranging from 300 to 500 °C. An EHD-jet-printed ZTO active layer was patterned with a 60 μm width using a 100 μm inner diameter metal nozzle. The electrical properties of an EHD-jet-printed ZTO TFT showed a mobility of 9.82 cm(2)/(V s), an on-off current ratio of 3.7 × 10(6), a threshold voltage of 2.36 V, and a subthreshold slope of 0.73 V/dec at 500 °C. Significantly improved properties were obtained compared to the spin-coated and inkjet-printed ones. Better hysteresis behavior and positive bias stability of the ZTO TFTs were also achieved using EHD-jet printing technology.