Effects of Cs deposition on the field-emission properties of single-walledcarbon-nanotube bundles

We report the effects of Cs deposition on the field-emission (FE) propertie s of single-walled carbon-nanotube bundles. We observe that Cs deposition d ecreases the turn-on field for FE by a factor of 2.1-2.8 and increases the FE current by six orders of magnitude. After Cs deposition, the FE current versus voltage (I-V) curves show non-Fowler-Nordheim behavior at large curr ents, consistent with tunneling from adsorbate states. At lower currents, t he ratio of the slope of the FE I-V curves before and after Cs deposition i s approximately 2.1. Exposure to N-2 does not decrease the FE current, whil e exposure to O-2 decreases the FE current. (C) 2001 American Institute of Physics.