Scaled fabrication of single-nanotube-tipped ends from carbon nanotube micro-yarns and their field emission applications

Joule-heating-induced electrical breakdown was applied to break suspended carbon nanotube (CNT) micro-yarns. The yarn ends at the breaking points were well-shaped sharp tips and mostly terminated by a single nanotube. The uppermost CNT was approximately 5 nm in diameter and was firmly compacted with the CNTs below it, yielding better mechanical, electrical and thermal contacts. An individual end could provide an emission current of approximately 25 μA, with potential application as a point electron source. In addition, we developed a pixel structure for a field emission display using oppositely aligned ends as the cathode and gate, respectively.