Transport-limited emission from carbon nanotubes

We have recently demonstrated emission from arrays of gated multiwall carbon nanotubes on silicon substrates. In addition to fabrication development, these structures are useful for study of the carbon nanotube emission properties. To that end, we have measured the effect of emission current, temperature, and gas environments on the energy distributions. We find that the emission near the Fermi level saturates at high currents, but the effect is reduced at elevated temperature. Because the emission threshold does not change, we believe the low electron density near E_F causes the saturation