Field Emission Study of Carbon Nanotubes: High Current Density from Nanotube Bundle Arrays

摘要

We have investigated the field emission behavior of lithographically patterned bundles of multiwalled carbon nanotubes arranged in a variety of array geometries. Such arrays of nanotube bundles are found to perform significantly better in field emission than arrays of isolated nanotubes or dense, continuous mats of nanotubes, with the field emission performance depending on the bundle diameter and inter-bundle spacing. Arrays of 2-μm diameter nanotube bundles spaced 5 μm apart (edge-to-edge spacing) produced the largest emission densities, routinely giving 1.5 to 1.8 A/cm~2 at ～ 4 V/μm electric field, and >6 A/cm~2 at 20 V/μm.