Effect of adsorbates on field emission from carbon nanotubes - art. no. 155502

Citation
A. Maiti et al., Effect of adsorbates on field emission from carbon nanotubes - art. no. 155502, PHYS REV L, 8715(15), 2001, pp. 5502
Citations number
29
Categorie Soggetti
Physics
Journal title
PHYSICAL REVIEW LETTERS
ISSN journal
00319007 → ACNP
Volume
8715
Issue
15
Year of publication
2001
Database
ISI
SICI code
0031-9007(20011008)8715:15<5502:EOAOFE>2.0.ZU;2-O
Abstract
Recent experiments indicate that water molecules adsorbed on carbon nanotub e tips significantly enhance field-emission current. Through first-principl es density-functional theory calculations we show that the water-nanotube i nteraction is weak in zero electric field. However, under emission conditio ns large electric field present at the tube tip: (a) increases the binding energy appreciably, thereby stabilizing the adsorbate; and (b) lowers the i onization potential (IP), thereby making it easier to extract electrons. Lo wering of IP is enhanced further through the formation of a water cluster o n the nanotube tip.