A real-space, real-time implementation of time-dependent density functional theory is used to study
electron field emission from nanostructures. Carbon nanotubes and graphene nanoribbons are used as
model systems. The calculations show that carbon nanotubes with iron adsorbates have spin-polarized
emission currents. Graphene nanoribbons are shown to be good field emitters with spatial variation of
the emission current influenced by the presence of passivating hydroge
