title: Effect of adsorbates on field emission from carbon nanotubes.
abstract: Recent experiments indicate that water molecules adsorbed on carbon nanotube tips significantly enhance field-emission current. Through first-principles density-functional theory calculations we show that the water-nanotube interaction is weak in zero electric field. However, under emission conditions large electric field present at the tube tip: (a) increases the binding energy appreciably, thereby stabilizing the adsorbate; and (b) lowers the ionization potential (IP), thereby making it easier to extract electrons. Lowering of IP is enhanced further through the formation of a water cluster on the nanotube tip.
authors.affiliation: Accelrys Inc., 9685 Scranton Road, San Diego, California 92121, USA. amaiti@accelrys.com
authors.forename: A
authors.initials: A
authors.lastname: Maiti
authors.forename: J
authors.initials: J
authors.lastname: Andzelm
authors.forename: N
authors.initials: N
authors.lastname: Tanpipat
authors.forename: P
authors.initials: P
authors.lastname: von Allmen