Robust and regenerable integrally gated carbon nanotube field emitter arrays

Abstract

Multiwalled carbon nanotubes (cNTs) in both the gated cNT-on-Si post and the cNT-in-open configurations were used in this study. Large increases in field emission current were observed when operating cNTs in substantial pressures of hydrogen, especially after the nanotubes have been contaminated with oxygen. Emission degradation was likely due to surface contamination with oxygen and was removed by reaction with hydrogen (atoms). Exposure of the emitters to molecular hydrogen or oxygen when the arrays are not emitting has no effect on the emission produced once the gases are removed, suggesting that the nanotubes are inert to the molecular forms of hydrogen and oxygen and that the atomic forms, which are created by electron dissociation, react with surface groups. The requirement for relatively high pressures of hydrogen also suggests that atomic hydrogen was responsible for the large enhancement and regeneration effects. The ability to regenerate emission from contaminated cNT can prolong emitter device lifetimes and save cost.