Field Emission with Ultralow Turn On Voltage from Metal Decorated Carbon Nanotubes

ACS Nano ◽  
2014 ◽  
Vol 8 (8) ◽  
pp. 7763-7770 ◽  
Author(s):  
Srividya Sridhar ◽  
Chandrasekhar Tiwary ◽  
Soumya Vinod ◽  
Jose Jaime Taha-Tijerina ◽  
Srividvatha Sridhar ◽  
...  
2001 ◽  
Vol 22 (11) ◽  
pp. 516-518 ◽  
Author(s):  
K.J. Chen ◽  
W.K. Hong ◽  
C.P. Lin ◽  
K.H. Chen ◽  
L.C. Chen ◽  
...  

2007 ◽  
Vol 7 (11) ◽  
pp. 3731-3735 ◽  
Author(s):  
Hyung Soo Uh ◽  
Sang Sik Park ◽  
Byung Whan Kim

We demonstrated that the diameter and the density of carbon nanotubes (CNTs) which had a close relation to electric-field-screening effect could be easily changed by the control of catalytic Ni thickness combined with NH3 plasma pretreatment. Since the diameter and the density of CNTs had a tremendous impact on the field-emission characteristics, optimized thickness of catalyst and application of plasma pretreatment greatly improved the emission efficiency of CNTs. In the field emission test using diode-type configuration, well-dispersed thinner CNTs exhibited lower turn-on voltage and higher field enhancement factor than the densely-packed CNTs. A CNT film grown using a plasma-pretreated 25 Å-thick Ni catalyst showed excellent field emission characteristics with a very low turn-on field of 1.1 V/μm @ 10 μA/cm2 and a high emission current density of 1.9 mA/cm2 @ 4.0 V/μm, respectively.


2012 ◽  
Vol 486 ◽  
pp. 47-50 ◽  
Author(s):  
Gang Chen ◽  
Hui Zhong Ma ◽  
Lan Zhang ◽  
Hong Ye Chen ◽  
Qiue Xia ◽  
...  

Three kinds of different diameter carbon nanotubes (CNTS) films deposited on aluminum sheets by electrophoretic deposition method. Scanning electron microscopy was used to observe the surface morphology of the films. The field emission properties of the films were tested by using a diode structure. The turn-on field for 8nm diameter CNTs film was 0.8V/μm and the current density of 5200μA/cm2 was obtained at 2.3V/μm. While corresponding data for 15nm and 30nm CNTs films were 1.6V/μm, 1.4V/μm, and 2200μA/cm2, 850μA/cm2 at 3.0V/μm respectively. The deposited film with 8nm diameter CNTs appeared excellent emission properties.


Author(s):  
D. G. Walker ◽  
T. S. Fisher

Carbon nanotubes (CNT) are being considered for field emission applications because of their low turn-on voltage and ability to support large current densities. The localization of emission and large currents from CNTs result in significant anode heating. The present work investigates the electron energy distribution at the anode surface through simulation of the field emission process and the trajectory of electrons across the vacuum gap. Field emission is modeled by Fowler-Nordheim-like expressions where the emission site is assumed to be a ring with the diameter of a nanotube. The electron trajectory is determined through a Monte Carlo simulation including Coulomb interactions between electrons. Results indicate that the electron beam spreads due to Coulomb interaction, but that the initial ring is preserved. In fact, the ring diameter at the anode spreads to 3μ per 10μ of vacuum gap in a field of 10 Vμm. This estimate matches well with reported observations. Further, the spreading becomes more significant with increased fields due to the higher current density of field emitted electrons.


2002 ◽  
Vol 727 ◽  
Author(s):  
Taewon Jeong ◽  
Jae Hee Han ◽  
Whikun Yi ◽  
SeGi Yu ◽  
Jeonghee Lee ◽  
...  

AbstractUsing a gas mixture of propyne (C3H4) and ammonia (NH3) as a carbon precursor, we have successfully synthesized multiwalled carbon nanotubes (CNTs) by the direct current (dc) plasma enhanced chemical vapor deposition (PECVD) onto Co-sputtered glass at 550°C. As the flow ratio of NH3 to C3H4 in the mixture gas increased, the crystallinity and alignment of CNTs were improved. In addition, the field emission characteristics of CNTs were also improved. the turn-on voltage became lower, and the current density and the field enhancement factor were more increasing. Raman spectroscopy and scanning electron microscopy were utilized to confirm the effect of the gas flow ratio on CNTs. Therefore, the gas flow ratio was found to be one of important factors to govern the crystalline and field emission characteristics of CNTs. The growth mechanism of CNTs using a C3H4 gas is under investigation with the possibility that three carbon atoms in a C3H4 molecule is converted directly to a hexagon of a CNT by combining two molecules.


2007 ◽  
Vol 7 (11) ◽  
pp. 3731-3735
Author(s):  
Hyung Soo Uh ◽  
Sang Sik Park ◽  
Byung Whan Kim

We demonstrated that the diameter and the density of carbon nanotubes (CNTs) which had a close relation to electric-field-screening effect could be easily changed by the control of catalytic Ni thickness combined with NH3 plasma pretreatment. Since the diameter and the density of CNTs had a tremendous impact on the field-emission characteristics, optimized thickness of catalyst and application of plasma pretreatment greatly improved the emission efficiency of CNTs. In the field emission test using diode-type configuration, well-dispersed thinner CNTs exhibited lower turn-on voltage and higher field enhancement factor than the densely-packed CNTs. A CNT film grown using a plasma-pretreated 25 Å-thick Ni catalyst showed excellent field emission characteristics with a very low turn-on field of 1.1 V/μm @ 10 μA/cm2 and a high emission current density of 1.9 mA/cm2 @ 4.0 V/μm, respectively.


2002 ◽  
Vol 750 ◽  
Author(s):  
Mann Yi ◽  
Hyuck Jung ◽  
Woo-Suk Seo ◽  
Jong-Won Park ◽  
Hyun-Tae Chun ◽  
...  

ABSTRACTCarbon nanotubes (CNTs) have been significantly used for the field emitters for display applications. It is necessary to investigate the process variables affecting the screen printing of carbon nanotubes for the fabrication of good-quality field emitter devices with uniformity. Screen printing techniques have some advantages such as the short processing time and lower processing cost. The carbon nanotube pastes for screen printing are normally composed of organic binders, carbon nanotubes, and some additive materials. In this study, the carbon nanotube emitters for field emission displays were fabricated with different processing variables such as paste viscosity, paste composition, screen mesh, etc. The CNT pastes were printed on Cr-coated/Ag-printed soda-lime glass substrates. As a result, the processing variables were optimized for the good screen printing. From the I-V characteristics, the turn-on field of single-walled nanotubes was lower than that of multi-walled nanotubes. The decrease in the mesh number of screen masks resulted in decreasing the turn-on field and increasing the electron emission current due to the higher density and vertical alignment of printed-CNTs.


2003 ◽  
Vol 772 ◽  
Author(s):  
Masakazu Muroyama ◽  
Kazuto Kimura ◽  
Takao Yagi ◽  
Ichiro Saito

AbstractA carbon nanotube triode using Helicon Plasma-enhanced CVD with electroplated NiCo catalyst has been successfully fabricated. Isolated NiCo based metal catalyst was deposited at the bottom of the cathode wells by electroplating methods to control the density of carbon nanotubes and also reduce the activation energy of its growth. Helicon Plasma-enhanced CVD (HPECVD) has been used to deposit nanotubes at 400°C. Vertically aligned carbon nanotubes were then grown selectively on the electroplated Ni catalyst. Field emission measurements were performed with a triode structure. At a cathode to anode gap of 1.1mm, the turn on voltage for the gate was 170V.


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