Pointwise Fabrication and Fluidic Shaping of Carbon Nanotube Field Emitters

We introduce a new method for fabricating fiber-like field emitters using pointwise deposition of aqueous suspensions of carbon nanotubes (CNTs). Liquid ink is held between a flat base and an upper locating pin as the ink solvent dries and CNTs densify via capillary forces. The resulting field emitters have high aspect ratios, dense packing of CNTs and, importantly, a large base providing mechanical stability and enhanced thermal/electrical contact compared to emitters fabricated from wet-spun CNT fibers and CNT forests. These attributes enable excellent field emission properties—namely, a high field enhancement factor and low turn-on voltage—for a range of tested emitter sizes. The noteworthy improvements in emission from these CNT structures alongside the versatile fabrication process motivates future work on emitter array manufacturing and device integration.