Self-heating controlled current-voltage and noise characteristics in graphene

Pulsed current-voltage characteristics have been measured for epitaxial SiC graphene under controlled lattice temperature conditions. The monolayer and AB stacked bilayer graphene is dry transferred on SiO2. The measured characteristics of two-terminal samples with coplanar electrodes demonstrate non-ohmic behaviour up to intermediate-high fields. At high currents thermal effects come into play and soft damage of the samples takes place. Bilayer graphene samples withstand 20 kV cm-1 electric field when few nanosecond voltages pulses are applied. The results are treated in terms of hole drift velocity estimated from the data on current under the assumption of uniform electric field and constant hole density. The highest velocity of ∼3.5-5 106 cm s-1 (∼1.5 107 cm s-1) is estimated for the bilayer (monolayer) graphene. The velocity results are interpreted with hot phonons. High frequency noise is measured at 10 GHz for the monolayer graphene and the associated shot noise is resolved.