Double-gate SnO2 nanowire electric-double-layer transistors with tunable threshold voltage

Double-gate Sb-SnO2 nanowire electric-double-layer (EDL) transistors with in-plane gates were fabricated using only one shadow mask. The threshold voltage of such devices can be tuned in a wide range from −0.13 V to 0.72 V by the in-plane gate, which allows the device to switch from depletion-mode to enhancement-mode operation. The operation voltage of the double-gate device is 1 V because the EDL gate dielectric can lead to a high gate capacitance (>3.5 μF/cm2). Moreover, all double-gate devices show good electrical characteristics with high field-effect mobility (>200 cm2/V·s), high drain-current Ion/off ratio (>7 × 104), and small subthreshold slope (<100 mV/dec). These double-gate nanowire EDL transistors can pave the way for an electrically working low-voltage nano-electronic process.