Evidence for adsorbate-enhanced field emission from carbon nanotube fibers

摘要

We used residual gas analysis (RGA) to identify the species desorbed during field emission (FE) from a carbon nanotube (CNT) fiber. The RGA data show a sharp threshold for H_2 desorption at an external field strength that coincides with a breakpoint in the FE data. A comprehensive model for the gradual transition of FE from adsorbate-enhanced CNTs at low bias to FE from CNTs with reduced H_2 adsorbate coverage at high bias is developed which accounts for the gradual desorption of the H_2 adsorbates, alignment of the CNTs at the fiber tip, and importance of self-heating effects with applied bias.