Humidity sensing properties of a single Sb doped SnO2 nanowire field effect transistor

This work reports the humidity dependent properties of a single Sb doped SnO2 nanowire field effect transistor (NWFET). The NWFET is fabricated by a lithography method on a highly doped silicon substrate as back gate covered by oxide as gate dielectric. The electric properties of the device under different relative humidities (RHs) at room temperature are investigated. The NWFET exhibits a field effect mobility of 108.7 cm2/(V s), a subthreshold swing of 70 mV/decade, and a drain current on/off ratio of 106. The threshold voltage shifts from −11.2 V to −14.6 V as RH increases from 22% to 40%. The NWFET exhibits sensitive behaviors to the humidity, which is promising for the application in humidity sensors.