High stability of emission current for a new carbon nanostructure film

We have studied the stability in the field emission currents for a carbon nanostructure which comprises of high-density carbon nanotips on Si. The emission current decreases by ∼18% after 50 h operation at ∼0.5 mA/cm2 and it fluctuates by ±2% during operation. The high stability in emission current may be due to the high density of carbon tips and stable material property of graphite. The fluctuation may be due to the absorption and desorption of molecules to the tips in a vacuum chamber during electron emission.