Highly efficient electron field emission from decorated multiwalled carbon nanotube films

The field emission properties of films of aligned multiwalled nanotubes produced by plasma-enhanced chemical vapor deposition are studied as a function of their length. The measured turn-on and threshold electric fields decrease strongly with increasing nanotube length, reaching values of below 1 V/μm for the longest nanotubes investigated (170 μm). The field enhancement factors are discussed and the remarkable performance of the longest nanotube films is attributed to secondary thornlike growth at the tips. \ua9 2004 American Institute of Physics