Effect of Catalyst Thickness and Plasma Pretreatment on the Growth of Carbon Nanotubes and Their Field Emission Properties

2007 ◽  
Vol 7 (11) ◽  
pp. 3731-3735 ◽  
Author(s):  
Hyung Soo Uh ◽  
Sang Sik Park ◽  
Byung Whan Kim
Keyword(s):  
Carbon Nanotubes ◽  
Field Emission ◽  
Field Enhancement ◽  
Close Relation ◽  
Emission Current Density ◽  
Ni Catalyst ◽  
Emission Characteristics ◽  
Field Emission Properties ◽  
Turn On ◽  
Plasma Pretreatment

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.

Effect of Catalyst Thickness and Plasma Pretreatment on the Growth of Carbon Nanotubes and Their Field Emission Properties

2007 ◽  
Vol 7 (11) ◽  
pp. 3731-3735
Author(s):  
Hyung Soo Uh ◽  
Sang Sik Park ◽  
Byung Whan Kim
Keyword(s):  
Carbon Nanotubes ◽  
Field Emission ◽  
Field Enhancement ◽  
Close Relation ◽  
Emission Current Density ◽  
Ni Catalyst ◽  
Emission Characteristics ◽  
Field Emission Properties ◽  
Turn On ◽  
Plasma Pretreatment

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.

Field emission characteristics of carbon nanotubes synthesized by C3H4 and NH3 gases

2002 ◽  
Vol 727 ◽  
Author(s):  
Taewon Jeong ◽  
Jae Hee Han ◽  
Whikun Yi ◽  
SeGi Yu ◽  
Jeonghee Lee ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Field Emission ◽  
Gas Flow ◽  
Field Enhancement ◽  
Chemical Vapor ◽  
Emission Characteristics ◽  
Flow Ratio ◽  
Multiwalled Carbon ◽  
Turn On ◽  
Gas Flow Ratio

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.

Field Emission Properies of CNTs Treated by Helium Plasma

2011 ◽  
Vol 347-353 ◽  
pp. 4008-4011
Author(s):  
Shao Lin Xue ◽  
Shu Xian Wu ◽  
Ran Huang ◽  
Zi Xin Jiang ◽  
Jian Fang Fang
Keyword(s):  
Field Emission ◽  
Emission Current Density ◽  
Treatment Method ◽  
Emission Characteristics ◽  
Helium Plasma ◽  
Turn On ◽  
Field Emission Current ◽  
Field Emission Current Density ◽  
Surface Morphologies ◽  
Screen Printed

This paper presented a novel post-treatment method of He plasma,which could effectively improve the field emission characteristics of screen-printed CNTs cathodes. Notable changes in the surface morphologies of screen-printed CNTs cathodes were investigated by scanning electron micro scope (SEM) as the f unction of treatment by He plasma.The results showed the post-treated CNTs cathodes hold lower turn-on electric field,higher field emission current density,more emission sites,and better uniformity than those of untreated ones.

Preparation and Field Emission Properties of Ag-CNTs by Electroless Plating

2010 ◽  
Vol 148-149 ◽  
pp. 983-986 ◽  
Author(s):  
Yu Xiang You ◽  
Yun Ye ◽  
Yi Jing Su ◽  
Qiao Zhi Tang ◽  
Tai Liang Guo
Keyword(s):  
Carbon Nanotubes ◽  
Field Emission ◽  
Electroless Plating ◽  
Emission Current Density ◽  
Small Radius ◽  
Radius Of Curvature ◽  
Emission Properties ◽  
Field Emission Properties ◽  
Pristine Cnts ◽  
Electrophoresis Deposition

Carbon nanotubes (CNTs) demonstrate attractive characteristics as cold cathode emitters for high aspect ratio, small radius of curvature, high mechanical strength and chemical stability. In this article, Ag-CNTs were prepared by a series of processes including acid-treating, sensitizing, activating and electroless plating. Then Ag-CNTs cathode were sucessfully fabricated by electrophoresis deposition (EPD) method. The morphologies of Ag-CNTs cathode and pristine CNTs cathode were observed by scanning electron microscopy (SEM). The results showed that the field emission properties of Ag-CNTs cathode were better than pristine CNTs cathode, for presenting lower turn-on field, larger emission current density, more stabilization and longer lifetime. Thus it can be seen that the Ag-CNTs cathode can improve the characteristics of carbon nanotubes field emission display (CNT-FED).

Synthesis of Carbon–Nitrogen Nanostructures by Hot Isostatic Pressure Apparatus and Their Field Emission Properties

2007 ◽  
Vol 7 (2) ◽  
pp. 570-574
Author(s):  
Yang Doo Lee ◽  
V. D. Blank ◽  
D. V. Batov ◽  
S. G. Buga ◽  
Yun-Hi Lee ◽  
...  
Keyword(s):  
Field Emission ◽  
Field Enhancement ◽  
Glass Frit ◽  
Gas Mixture ◽  
Nitrogen Gas ◽  
Field Emission Properties ◽  
Turn On ◽  
Field Emitters ◽  
Enhancement Factors ◽  
Resistive Heater

Carbon–nitrogen (CN) nanofibers were synthesized in argon–nitrogen gas mixture at 75 MPa by high isostatic pressure (HIP) apparatus using a graphite resistive heater. The CN nanofibers were grown in random with the diameter of about 200 nm and the length over 5 μm. The structures obtained can be divided bamboo-like, spring-like, and bead necklace-like CN nanofibers. The nitrogen content of up to 8.4% was found in CN nanofibers by EELS analysis. Field emission results showed that the density of field emitters and the field enhancement factors changed by surface treatments and that CN nanofibers contained glass frit. The screen-printed CN nanofiber had a turn-on field of 2 V/μm.

The Effect of Thermal Accumulation to the Field Emission Properties of the Carbon Nanotubes

2015 ◽  
Vol 645-646 ◽  
pp. 265-268
Author(s):  
Fei Yan ◽  
Nan Nan Li ◽  
Lei Chen ◽  
Da Zhi Jin ◽  
Wei Xiang
Keyword(s):  
Carbon Nanotubes ◽  
Experimental Observation ◽  
Field Emission ◽  
Current Density ◽  
Pulse Mode ◽  
Emission Characteristics ◽  
Emission Properties ◽  
Good Linear ◽  
Field Emission Properties ◽  
Linear Fit

In this paper, we report a recent experimental observation of the effect of thermal accumulation to the field emission properties of the carbon nanotubes. The carbon nanotubes are grown on Ni by CVD. We compare the field emission characteristics of carbon nanotubes cathodes under DC and pulse mode. Our research shows that the higher current and higher current density could be acquired by suppressing the thermal accumulation. The Fowler-Nordheim plot shows a good linear fit, indicating that the emission current of carbon nanotubes follows Fowler-Nordheim behavior.

Sign in / Sign up

Export Citation Format

Share Document