Jump to Content
Your Recent History
View Cart
You are not logged in to this journal. Log In
J. Vac. Sci. Technol. B 18, 665 (2000); http://dx.doi.org/10.1116/1.591258 (14 pages)
Field emission properties of carbon nanotubes
Alerts
Alert Me When Cited
Alert Me When Corrected
Tools
Download Citation
Add to MyScitation
Permissions / Reprints
Blog This Article
Print-Friendly
Research Toolkit
Share
Email Abstract
Connotea
CiteULike
del.icio.us
BibSonomy
Tweet this Article
Add to FacebookWe have investigated the field emission properties of nanotube thin films deposited by a plasma enhanced chemical vapor deposition process from 2% CH4 in H2 atmosphere. Depending on the deposition of the metallic catalyst [Fe(NO3)3 in an ethanol solution or sputtered Ni] the nanotube films showed a nested or continuous dense distribution of tubes. The films consisted of multiwalled nanotubes (MWNTs) with diameters ranging from 40 down to 5 nm, with a large fraction of the tubes having open ends. The nanotube thin film emitters showed a turn-on field of less than 2 V μm−1 for an emission current of 1 nA. An emission site density of 10 000 emitters per cm−2 is achieved at fields around 4 V μm−1. The emission spots, observed on a phosphorous screen, show various irregular structures, which we attribute to open ended tubes. A combined measurement of the field emitted electron energy distribution (FEED) and the current-voltage characteristic allowed us to determine the work function at the field emission site. In the case of the MWNT thin films and arc discharge grown MWNTs we found work function values around 5 eV, which agree well with the global work function of 4.85 eV we determined by photoelectron spectroscopy. From the shape of the FEED peaks we can conclude that the field emission originates from continuum states at the Fermi energy, indicating the metallic character of the emission site. In the case of single-walled nanotubes we found significantly lower work function values of around 3.7 eV compared to those of MWNTs. We attribute this to a size dependent electrostatic effect of the image potential, which lowers the work function for small (<5 nm) structures. © 2000 American Vacuum Society.
© 2000 American Vacuum Society
KEYWORDS and PACS
History
Received 6 May 1999
Accepted 7 January 2000
Accepted 7 January 2000
Digital Object Identifier
For access to fully linked references, you need to log in.
For access to citing articles, you need to log in.
This Publication
Scitation
SPIN
Scitopia
Google Scholar
PubMed