Electron cold sources: Nanotechnology contribution to field emitters

2017 ◽  
Author(s):  
Vu Thien Binh
Keyword(s):  
Carbon Nanotubes ◽  
Carbon Nanotube ◽  
Field Emission ◽  
Driving Forces ◽  
Industrial Applications ◽  
Single Atom ◽  
Cold Cathodes ◽  
Field Emitters ◽  
Carbon Nanopearls ◽  
Field Emission Cathodes

This article reviews recent advances in field emission cathodes and their applications, focusing on a number of possibilities emerging from the field of nanotechnology. It begins with an overview of the driving forces for the evolution of cold cathodes, laying emphasis on their fundamental characteristics and industrial applications as well as the bottlenecks of metallic field emitters. It then considers single-atom emitters, followed by different examples where the advent of nanotechnology has contributed towards improving new cold cathodes. It also discusses the Fresnel projection microscope and the microgun, a route to the microcolumn approach which is associated with the nanotip; a host of material issues for field emitters, taking into account carbon nanocompounds; carbon-nanotube field emitters; and carbon-nanopearl field emitters. The article concludes with an evaluation of the applications and uses of carbon nanocompounds, carbon nanotubes and carbon nanopearls as cold cathodes.

Enhanced Field Emission Properties of Carbon Nanotube Based Field Emitters by Dynamic Oxidation

2013 ◽  
Vol 9 (5) ◽  
pp. 619-623 ◽  
Author(s):  
Shama Parveen ◽  
Samina Husain ◽  
Avshish Kumar ◽  
Javid Ali ◽  
Mubashshir Husain ◽  
...  
Keyword(s):  
Carbon Nanotube ◽  
Field Emission ◽  
Emission Properties ◽  
Field Emission Properties ◽  
Field Emitters ◽  
Dynamic Oxidation

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.

Magnesium and Aluminium Carbon Nanotube Composites

2010 ◽  
Vol 425 ◽  
pp. 245-261 ◽  
Author(s):  
C.S. Goh ◽  
Manoj Gupta ◽  
Anders W.E. Jarfors ◽  
Ming Jen Tan ◽  
J. Wei
Keyword(s):  
Carbon Nanotubes ◽  
Carbon Nanotube ◽  
Detrimental Effect ◽  
Industrial Applications ◽  
Nanosized Materials ◽  
Nanotube Composites ◽  
Slip Planes ◽  
Carbon Nanotube Composites ◽  
Hcp Structure ◽  
Strength And Stiffness

Carbon nanotubes are one of the most exciting discoveries of nanosized materials in the 20th century. Challenges to create materials applicable for industrial applications involve both the incorporation of the carbon nanotubes into the material and to ensure that they do not agglomerate. Aluminium and magnesium based materials are among the metals that can benefit from the incorporation of carbon nanotubes. The fabrication of Aluminium carbon nanotube composites has challenges from reactivity and degradation of the carbon nanotube additions; hence the powder metallurgy route is preferred. Magnesium based materials on the other hand do not have this limitation and both the powder metallurgical route and the casting route are viable. Among the benefits of adding carbon nanotubes are increased yield strength and stiffness. Here is important that the effect is significant already at very low addition levels. This makes it possible to increase strength without having a significant detrimental effect on ductility. In fact, for magnesium alloys ductility can be improved due to the activation of additional slip planes improving the normally low ductility of HCP structure materials.

Improved Field-Emission Properties of Carbon Nanotube Field-Emission Arrays by Controlled Density Growth of Carbon Nanotubes

2005 ◽  
Vol 44 (1A) ◽  
pp. 365-370 ◽  
Author(s):  
Chuan-Ping Juan ◽  
Kuo-Ji Chen ◽  
Chun-Chien Tsai ◽  
Kao-Chao Lin ◽  
Wei-Kai Hong ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Carbon Nanotube ◽  
Field Emission ◽  
Emission Properties ◽  
Field Emission Properties ◽  
Density Growth ◽  
Field Emission Arrays

Study of Field Emission Behavior of Carbon Nanotubes with Different Sources

2002 ◽  
Vol 728 ◽  
Author(s):  
Mark Ching-Cheng Lin ◽  
M.S. Lai ◽  
H. J. Lai ◽  
M. H. Yang ◽  
B.Y. Wei ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Carbon Nanotubes ◽  
Carbon Nanotube ◽  
Field Emission ◽  
Arc Discharge ◽  
Metal Catalyst ◽  
Microstructural Investigation ◽  
Emission Properties ◽  
Field Emission Properties ◽  
Different Sources

AbstractThe field emission properties of carbon nanotubes (CNTs) from various sources are investigated for the application of field emission displays. Comparisons are made between graphite with Ni metal as catalyst and polycyclic aromatic hydrocarbon as precursor by the arc discharge method. Cathode deposits are examined using scanning electron microscopy (SEM) and high-resolution transmission electron microscopy (HRTEM) to determine microstructure. Carbon structure is studied using Raman spectroscopy. Electron field emission characteristics are measured with the diode method at 10-6 torr pressure. In this study, SEM micrographs of cathode deposits show dense random fiber-like carbon nanotubes. The HRTEM images clearly exhibit characteristic features of multiwalled carbon nanotubes. Microstructural investigation provides evidence that both the metal catalyst and the precursor can be used to synthesize carbon nanotubes. The Raman spectrum shows a stronger peak at about 1580 cm-1 indicating formation of a well-graphitized carbon nanotube. The degree of carbon nanotube graphitization is high and is in good agreement with the HRTEM result. From field emission measurements, the lowest onset field is about 1.0 V/μm and can be attributed to highly sharp tips and the high density of carbon nanotubes. Based on microstructure characterization and field emission measurements, the influence on field emission properties including turn on voltage and threshold voltage of carbon nanotubes synthesized from different sources is discussed.

Room-temperature fabrication of high-resolution carbon nanotube field-emission cathodes by self-assembly

2003 ◽  
Vol 82 (15) ◽  
pp. 2521-2523 ◽  
Author(s):  
S. J. Oh ◽  
Y. Cheng ◽  
J. Zhang ◽  
H. Shimoda ◽  
O. Zhou
Keyword(s):  
Carbon Nanotube ◽  
High Resolution ◽  
Field Emission ◽  
Self Assembly ◽  
Room Temperature ◽  
Field Emission Cathodes

Carbon nanotube cathodes covered on the cylindrical surface of a fiber

RSC Advances ◽  
2015 ◽  
Vol 5 (22) ◽  
pp. 17049-17053 ◽  
Author(s):  
Xianqi Wei ◽  
Youzhang Zhu ◽  
Xianjun Xia ◽  
Xiaoli Wang ◽  
Weihuan Liu ◽  
...  
Keyword(s):  
Chemical Vapor Deposition ◽  
Carbon Nanotube ◽  
Field Emission ◽  
Vapor Deposition ◽  
Cylindrical Surface ◽  
Chemical Vapor ◽  
Quartz Optical Fiber ◽  
Cnt Arrays ◽  
Field Emission Cathodes ◽  
Waveguide Surface

Carbon nanotube (CNT) arrays were synthesized on the cylindrical waveguide surface of a quartz optical fiber by chemical vapor deposition (CVD) to serve as field emission cathodes.

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