Low-frequency noise and hysteresis in graphene field-effect transistors on oxide

The authors report measurements of low-frequency noise and hysteresis in graphene monolayer and bilayer field-effect transistors (FETs) fabricated on 90 and 290 nm oxidised silicon substrates. The authors observe hysteresis induced by stressing the oxide up to fields of 2 MV/cm and have characterised the hysteresis against stress time and sample temperature. Low-frequency current noise with a 1/f2 spectral density arises from the drift of neutrality point voltage, and subsequent drift of graphene FET channel current. A simple model of charge trapping at the graphene–oxide interface and thermally activated ion motion accounts for the temperature dependence of the observed hysteresis.