On the mechanism of field emission from mechanical pencil lead

The perpendicularly cut end of the carbonized mechanical pencil lead shows superior field emission (FE) features, that is, the lower threshold electric field, the extremely lower effective work function, and the quite higher maximum current density, even though the corner edge is rounded. In this paper, we have discussed the mechanism of the superior FE features on the basis of the comparison with FE current and FIM/FEM images of the HOPG edges. The graphene edge existing on the pencil lead end is a dominant candidate of the emission site, giving the superior FE features.