Simulation study of junction effect on field emission from one-dimensional nanostructure grown on silicon substrates

Field emission properties of the one-dimensional nanostructure grown on doped silicon substrate are studied via computer simulation. The classical transport equation is used to describe the carrier transportation in the material and is solved coupled with the Poisson's equation. The field emission process between emitter and vacuum interface is modeled by the Fowler-Nordheim equation. For studying the space-charge screening effect, the carriers are allowed to move in the vacuum region, and the space-charge fields of the carriers are also solved self-consistently through the Poisson's equation. After the simulation, the F-N plot, the carrier distribution and the band structures are figured out. The simulation results of the anode current as a function of the applied voltage for single SiCN grown on n- and p-type doped silicon substrates are shown. The simulation results exhibit that the p-type substrate will limit the emission currents of the narrow- and wide-band-gap nanostructure at the high-field region. And the space-charge screening effect will further saturate the emission current.