Flexible electric-double-layer (EDL) thin film transistors (TFTs) based on a vertical InGaZnO4 (IGZO) channel are fabricated at room temperature. Such TFTs show a low operation voltage of 1.0 V due to the large specific gate capacitance of 3.8 μF cm−2 related to electric-double-layer formation. The threshold voltage, drain current on/off ratio and subthreshold swing are estimated to be −0.1 V, 1.2 × 106 and 80 mV per decade, respectively. The combination of low voltage, high current on-to-off ratio and room temperature processing make the flexible vertical-IGZO-channel TFTs very promising for low-power portable flexible electronics applications.
