Combustion-assisted low-temperature ZrO2/SnO2 films for high-performance flexible thin film transistors

We developed high-performance flexible oxide thin-film transistors (TFTs) using SnO 2 semiconductor and high-k ZrO 2 dielectric, both formed through combustion-assisted sol-gel processes. This method involves the exothermic reaction of fuels and oxidizers to produce high-quality oxide films without extensive external heating. The combustion ZrO 2 films were revealed to have an amorphous structure with a higher proportion of oxygen corresponding to the oxide network, which contributes to the low leakage current and frequency-independent dielectric properties. The ZrO 2 /SnO 2 TFTs fabricated on flexible substrates using combustion synthesis exhibited excellent electrical characteristics, including a field-effect mobility of 26.16 cm 2 /Vs, a subthreshold swing of 0.125 V/dec, and an on/off current ratio of 1.13 × 10 6 at a low operating voltage of 3 V. Furthermore, we demonstrated flexible ZrO 2 /SnO 2 TFTs with robust mechanical stability, capable of withstanding 5000 cycles of bending tests at a bending radius of 2.5 mm, achieved by scaling down the device dimensions.