scholarly journals Effect of heating and resistance on emission properties of carbon nanotubes

2018 ◽  
Vol 2 (2) ◽  
Author(s):  
Sergey V. Bulyarskiy 1 ◽  
Alexander A. Dudin 1 ◽  
Alexander V. Lakalin 1 ◽  
Andrey P. Orlov 1 ◽  
Alexander A. Pavlov 1 ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Field Emission ◽  
Thermionic Emission ◽  
Negative Resistance ◽  
Cvd Method ◽  
Field Emission Current ◽  
Multi Walled Carbon Nanotube ◽  
Voltage Current Characteristic ◽  
Field Emission Of Electrons ◽  
A Current

We have studied the effect of the series resistance on the heating of the cathode, which is based on carbon nanotubes and serves to realize the field emission of electrons into the vacuum. The experiment was performed with the single multi-walled carbon nanotube (MCNT) that was separated from the array grown by CVD method with thin-film Ni-Ti catalyst (nickel 4 nm / Ti 10 nm). The heating of the cathode leads to the appearance of a current of the thermionic emission. The experimental voltage current characteristic exhibited the negative resistance region caused by thermal field emission. This current increases strongly with increasing voltage and contributes to the degradation of the cold emitter. The calculation of the temperature of the end of the cathode is made taking into account the effect of the phenomenon that warms up and cools the cathode. We have developed a method for processing of the emission volt-ampere characteristics of a cathode, which relies on a numerical calculation of the field emission current and the comparison of these calculations with experiments. The model of the volt-ampere characteristic takes into account the CNT’s geometry, properties, its contact with the catalyst; heating and simultaneous implementation of the thermionic and field emission. The calculation made it possible to determine a number of important parameters, among which the voltage and current of the beginning of thermionic emission, the temperature distribution along the cathode, the resistance of the nanotube. The phenomenon of thermionic emission from CNT’s was investigated experimentally and theoretically. The conditions of this type emission occurrence were defined. The results of the study could form the basis of theory of CNT emitter’s degradation.

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.

Thermal Transport During Nanoscale Machining by Field Emission of Electrons from Carbon Nanotubes

2003 ◽  
Vol 125 (4) ◽  
pp. 546-546 ◽  
Author(s):  
C. Trinkle ◽  
P. Kichambare ◽  
R. R. Vallance ◽  
B. Sadanadan ◽  
A. M. Rao ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Field Emission ◽  
Thermal Transport ◽  
Field Emission Of Electrons

scholarly journals Field Emission Properties of Carbon Nanotubes with Boron Doping and H2O Adsorption

2013 ◽  
Vol 2013 ◽  
pp. 1-6
Author(s):  
Yijun Wang ◽  
Liuding Wang ◽  
Cheng Yan
Keyword(s):  
Carbon Nanotubes ◽  
Field Emission ◽  
Boron Atom ◽  
Gas Adsorption ◽  
Mulliken Charge ◽  
Electronic Density ◽  
Emission Properties ◽  
Field Emission Properties ◽  
Electron Field ◽  
Field Emission Of Electrons

Gas adsorption and atom doping usually present when preparing carbon nanotubes (CNTs) and can affect the field emission properties of carbon nanotubes. H2O molecule and boron atom are the most important adsorbates, respectively. Using ab-initio calculations, we have investigated the electron field emission performance of CNTs simultaneously adsorbed with one H2O molecule and doped with one boron atom (BCNT+H2O) in this paper. The results indicate that the electrons localize at the top of BCNT+H2O and the electronic density of states (DOS) around the Fermi level is enhanced obviously. It is expected that BCNT+H2O will be more propitious to the field emission of electrons based on the calculations of DOS, HOMO/LUMO, and Mulliken charge population.

Field Emission Properties of Individual Carbon Nanotubes in Nanorobotic Manipulation and Electron-Beam-Induced Deposition

2004 ◽  
Vol 16 (6) ◽  
pp. 597-603 ◽  
Author(s):  
Fumihito Arai ◽  
◽  
Pou Liu ◽  
Lixin Dong ◽  
Toshio Fukuda ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Electron Beam ◽  
Field Emission ◽  
Emission Current ◽  
Emission Properties ◽  
Field Emission Properties ◽  
Field Emission Current ◽  
Multi Walled Carbon Nanotubes ◽  
Electron Beam Induced Deposition ◽  
Afm Cantilever

Field emission properties of individual multi-walled carbon nanotubes (MWNTs) were studied in nanorobotic manipulation and electron-beam-induced deposition (EBID). Nanotube emitters are constructed by picking up and assembling individual nanotubes on a commercially available atomic force microscope (AFM) cantilever or a tungsten probe. The relationship between field emission current and interelectrode distance was obtained by changing the distance between the tip of the nanotube emitter and the counterpart anode, which can be potentially applied as the principle for an approaching sensor to detect nanometer scale distance by observing field emission current in real time. Field emission current on a microampere scale from a CNT emitter was shown to be strong enough for EBID without obviously degrading emitters. Deposit topology was related to current density or the emitter shape, suggesting that information on emitter geometry could be obtained from EBID deposits. Energy dispersive X-ray spectrometry (EDS) analysis of deposits from W(CO)6showed that the tungsten mass exceeds 80% on the average among compositions. Much higher voltage may degrade the emitter, and saturated current may be used to adjust the emitter length in a controlled way.

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