Microgated in-situ grown carbon nanotube field emitter arrays

摘要

Incorporating carbon nanotubes (cNTs) into an integrated triode structure is necessary to enable field emission at low voltage. We have grown multi-walled cNTs by chemical vapor deposition on two types of gated structures, one containing a silicon post, another having an open aperture. Thresholds below 20V and total emission currents up to 1 mA at 40V (from 1mm~2 area) have been observed. The gated arrays emit stable currents without electrical arcing. Elevated temperature increased the emission current, as did ambient water vapor and hydrogen. The emission was unaffected by xenon up to 10~(-5) torr. The tubes grown in open apertures produced the lowest gate current of any cNT field emitter arrays (FEAs). Electron energy distributions reveal a current saturation phenomenon at energies just below the Fermi level, suggesting a limit in electron transport at the emission site.