Field emission from graphene flakes

We report the observation and characterization of field emission current from individual single- and few-layer graphene flakes laid on a flat SiO2 / Si substrate. Measurements were performed in a scanning electron microscope chamber equipped with nanoprobes which allowed local measurement of the field emission current. We achieved field emission currents up to 1μA from the flat part of graphene flakes at applied fields of few hundred volt per micrometer. We found that the emission process is stable over a period of several hours and that it is well described by a Fowler–Nordheim model for currents over five orders of magnitude.