Oriented Carbon Nanotube Growth for Field Emission Applications

1999 ◽  
Vol 558 ◽  
Author(s):  
A.N. Obraztsov ◽  
I. Pavlovsky ◽  
A.P. Volkov ◽  
V.L. Kuznetsov ◽  
A.L. Chuvilin

ABSTRACTOriented carbon nanotube films were grown using a method of chemical vapor deposition in hydrogen/methane plasma activated by glow discharge. The film phase composition and structural features were studied by Raman, SEM, TEM, and HRTEM techniques. Field emission properties of the films were examined to obtain I-V characteristics and the field emission site distribution. The I-V curves in Fowler-Nordheim coordinates were linear, that is typical for the field emission, with the threshold average field about 1.5 V/μm and the emission current density up to 50 mA/cm2 at the field of 5 V/μm. The emission site density reached 107 cm2 at the same value of electrtic field.

2014 ◽  
Vol 1035 ◽  
pp. 3-6
Author(s):  
Jin Hai Gao ◽  
Zhen Li ◽  
Wu Qing Zhang

The sphere-like diamond microcrystalline-aggregates were fabricated by microwave plasma chemical vapor deposition (MPCVD) method. The ceramic with a Ti metal layer was used as substrates. The fabricated diamond microcrystalline aggregates were evaluated by Raman scattering spectroscopy, x-ray diffraction spectrum (XRD), scanning electron microscopy (SEM). The field emission properties were tested by using a diode structure in a vacuum. A phosphor-coated indium tin oxide (ITO) anode was used for observing and characterizing the field emission. It was found that the sphere-like diamond microcrystalline-aggregates films exhibited good electron emission properties. The turn-on field was only 0.55V/μm, and emission current density as high as 11mA/cm2 was obtained under an applied field of 2.18V/μm for the first operation. After several cycling operations, the field emission tended to stable characteristics of current versus voltage. The stability evolvement and mechanism are investigated relating to microstructure of the sphere-like diamond microcrystalline-aggregates films.


1998 ◽  
Vol 509 ◽  
Author(s):  
Xueping Xu ◽  
George R. Brandes

AbstractA vacuum microelectronic device containing carbon nanotube electron field-emitters was developed and tested. The gated cathode was fabricated using conventional microelectronics fabrication techniques and a final, self-aligned, in situ carbon nanotube growth step. To our knowledge, this is the first vacuum microelectronics device with carbon nanotube field-emitters grown in situ with a catalytic growth process. The turn-on voltage of the cathode was less than 20 volts and the emission current density at 50 volts was as high as 9 mA-cm−2. The fabrication process, device performance, manufacturing issues and cathode applications will be discussed.


2005 ◽  
Vol 901 ◽  
Author(s):  
Han Zhang ◽  
Jie Tang ◽  
Qi Zhang ◽  
Gongpu Zhao ◽  
Guang Yang ◽  
...  

AbstractFor field-induced electron emission, the two factors that enable a high emission current density at low applied voltages are (a) low work function of the emitter and (b) sharpness of the emitter tip. We have developed and applied a chemical vapor deposition method to synthesize single-crystalline LaB6 nanowires for applications as point electron emitters. The crystallographic orientation of the grown nanowires can be controlled by the catalysts used in synthesis and their typical diameter is ranged from below 20 nm to over 100 nm. The nanowires’ tip is either hemispherical or flat top with rectangular cross-section depending on the catalyst being utilized. The field emission properties have also been measured from the single nanowire emitters and the results are discussed for applications as point electron sources used in high performance electron optical instruments such as the transmission and scanning electron microscopes.


Author(s):  
Jeffrey J. Lombardo ◽  
Wilson K. S. Chiu

Even though a large number of applications for multiwalled carbon nanotubes have been proposed, there is relatively limited knowledge about the optimal conditions in which to create multiwalled carbon nanotubes (MWNTs). Computational models have been shown to be a promising tool to determine the best carbon nanotube growth conditions. In this paper the growth of MWNTs in a tube flow CVD reactor was studied through the use of the commercial software package COMSOL, where details steps have been described to reformulate an existing single walled carbon nanotube (SWNT) growth model to accommodate MWNTs followed by validation and growth rate prediction. Higher growth rates were predicted for MWNTs than SWNTs which is a result of the increase in pathways for carbon to form carbon nanotubes based on the additional walls. Results indicate that selecting the correct number of walls can be important to the results of the model.


Carbon ◽  
2010 ◽  
Vol 48 (4) ◽  
pp. 1279-1288 ◽  
Author(s):  
Charlotte T.M. Kwok ◽  
Brandon J. Reizman ◽  
Daniel E. Agnew ◽  
Gurjit S. Sandhu ◽  
J. Weistroffer ◽  
...  

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