Thermionic emission from carbon nanotubes with a thin layer of low work function barium strontium oxide surface coating

2006 ◽  
Vol 88 (16) ◽  
pp. 163116 ◽  
Author(s):  
Feng Jin ◽  
Yan Liu ◽  
Christopher M. Day
Keyword(s):  
Carbon Nanotubes ◽  
Thin Layer ◽  
Work Function ◽  
Surface Coating ◽  
Thermionic Emission ◽  
Oxide Surface ◽  
Strontium Oxide ◽  
Barium Strontium

A New Thermionic Cathode Based on Carbon Nanotubes with a Thin Layer of Low Work Function Barium Strontium Oxide Surface Coating

2008 ◽  
Vol 1142 ◽  
Author(s):  
Feng Jin ◽  
Yan Liu ◽  
Scott A Little ◽  
Chris M Day
Keyword(s):  
Work Function ◽  
Current Density ◽  
Enhancement Factor ◽  
Thermionic Emission ◽  
Field Enhancement ◽  
Oxide Coating ◽  
Emission Current Density ◽  
Emission Current ◽  
Strontium Oxide ◽  
Barium Strontium

ABSTRACTWe have created a thermionic cathode structure that consists of a thin tungsten ribbon; carbon nanotubes (CNTs) on the ribbon surface; and a thin layer of low work function barium strontium oxide coating on the CNTs. This oxide coated CNT cathode was designed to combine the benefits from the high field enhancement factor from CNTs and the low work function from the emissive oxide coating. The field emission and thermionic emission properties of the cathode have been characterized. A field enhancement factor of 266 and a work function of 1.9 eV were obtained. At 1221 K, a thermionic emission current density of 1.22A/cm2 in an electric field of 1.1 V/μm was obtained, which is four orders of magnitude greater than the emission current density from the uncoated CNT cathode at the same temperature. The high emission current density at such a modest temperature is among the best ever reported for an oxide cathode.

Thermionic emission properties and the work function determination of arrays of conical carbon nanotubes

2013 ◽  
Vol 34 ◽  
pp. 1-8 ◽  
Author(s):  
Andriy Sherehiy ◽  
Santoshrupa Dumpala ◽  
Abdelilah Safir ◽  
David Mudd ◽  
Ivan Arnold ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Work Function ◽  
Thermionic Emission ◽  
Emission Properties

Barium strontium oxide coated carbon nanotubes as field emitters

2007 ◽  
Vol 90 (14) ◽  
pp. 143114 ◽  
Author(s):  
Feng Jin ◽  
Yan Liu ◽  
Christopher M. Day
Keyword(s):  
Carbon Nanotubes ◽  
Strontium Oxide ◽  
Field Emitters ◽  
Barium Strontium ◽  
Coated Carbon

scholarly journals Carbon Nanotube Electron Sources: From Electron Beams to Energy Conversion and Optophononics

2014 ◽  
Vol 2014 ◽  
pp. 1-23 ◽  
Author(s):  
Alireza Nojeh
Keyword(s):  
Carbon Nanotubes ◽  
Field Emission ◽  
Electron Emission ◽  
Electron Beams ◽  
Thermionic Emission ◽  
Secondary Emission ◽  
Electron Sources ◽  
Field Emitters ◽  
Electron Microscopes ◽  
Electron Emitters

Carbon nanotubes have a host of properties that make them excellent candidates for electron emitters. A significant amount of research has been conducted on nanotube-based field-emitters over the past two decades, and they have been investigated for devices ranging from flat-panel displays to vacuum tubes and electron microscopes. Other electron emission mechanisms from carbon nanotubes, such as photoemission, secondary emission, and thermionic emission, have also been studied, although to a lesser degree than field-emission. This paper presents an overview of the topic, with emphasis on these less-explored mechanisms, although field-emission is also discussed. We will see that not only is electron emission from nanotubes promising for electron-source applications, but also its study could reveal unusual phenomena and open the door to new devices that are not directly related to electron beams.

Thermoelectric and Thermionic Emission Properties of Carbon Nanotubes

2004 ◽  
Author(s):  
Chris Evans ◽  
Brian Landi ◽  
Ryne Raffaelle ◽  
Isay Krainsky ◽  
Sheila Bailey ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Thermionic Emission ◽  
Emission Properties
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