Abnormal electron emission from individual self-joule-heated carbon nanotubes

Electron emission from individual self-Jouleheated carbon nanotubes (CNTs) is found to deviate from Richardson´s law with emission current more than one order of magnitude larger than that predicted by Richardson´s law. The spatial distribution of the regarded electron emission is asymmetric along nanotube axis, and depends on the direction of electric field inside nanotube in addition to temperature distribution. The abnormal electron emission is attributed to the non-equilibrium distribution of electrons in CNTs when they are highly electrically biased, implying the potential to directly drive electron emission by an internal electric field.