Fe catalytic growth, microstructure, and low-threshold field emission properties of open ended tubular graphite cones

NG Shang, P Papakonstantinou, JAD McLaughlin, WC Chen, LC Chen, M Chu, A Stamboulis

Research output: Contribution to journalArticle

8 Citations (Scopus)

Abstract

Large-area tubular graphite cones (TGCs) with an open end were successfully synthesized on Si substrates by microwave plasma assisted chemical vapor deposition using a thin Fe film as catalyst. As-grown TGCs are uniformly distributed on the Si surface with a density of 5.8x10(5)/cm(2) and an average growth rate of 0.6 mu m/min. Some of them are very sharp with an apex angle as small as 2 degrees-3 degrees. Combined observations by transmission electron microscopy and cross-sectional scanning electron microscopy clarified that the TGCs possess a hollow nanotube core, a metal-free open tip and that the Fe catalyst is located in the root, strongly supporting the base-growth mechanism of TGCs. Scanning confocal micro-Raman spectroscopy along an individual TGC shows that the integrated intensity ratio of D to G band of individual TGC at tips (0.12) is an order of magnitude less than that at roots (1.2), confirming that the tip is highly crystalline whereas the root is of poor quality. Their field emission performance exhibits a turn-on field as low as 1.8 V/mu m and highly stable emission characteristics. The present study opens the way to site selective growth of TGCs and demonstrates its use as a potentially excellent emitter. (C) 2008 American Institute of Physics.
LanguageEnglish
Pages124308
JournalJournal of Applied Physics
Volume103
Issue number12
DOIs
Publication statusPublished - Jun 2008

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field emission
cones
graphite
microstructure
thresholds
catalysts
hollow
nanotubes
emitters
apexes
Raman spectroscopy
vapor deposition
microwaves
transmission electron microscopy
scanning electron microscopy
scanning
thin films
metals

Cite this

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title = "Fe catalytic growth, microstructure, and low-threshold field emission properties of open ended tubular graphite cones",
abstract = "Large-area tubular graphite cones (TGCs) with an open end were successfully synthesized on Si substrates by microwave plasma assisted chemical vapor deposition using a thin Fe film as catalyst. As-grown TGCs are uniformly distributed on the Si surface with a density of 5.8x10(5)/cm(2) and an average growth rate of 0.6 mu m/min. Some of them are very sharp with an apex angle as small as 2 degrees-3 degrees. Combined observations by transmission electron microscopy and cross-sectional scanning electron microscopy clarified that the TGCs possess a hollow nanotube core, a metal-free open tip and that the Fe catalyst is located in the root, strongly supporting the base-growth mechanism of TGCs. Scanning confocal micro-Raman spectroscopy along an individual TGC shows that the integrated intensity ratio of D to G band of individual TGC at tips (0.12) is an order of magnitude less than that at roots (1.2), confirming that the tip is highly crystalline whereas the root is of poor quality. Their field emission performance exhibits a turn-on field as low as 1.8 V/mu m and highly stable emission characteristics. The present study opens the way to site selective growth of TGCs and demonstrates its use as a potentially excellent emitter. (C) 2008 American Institute of Physics.",
author = "NG Shang and P Papakonstantinou and JAD McLaughlin and WC Chen and LC Chen and M Chu and A Stamboulis",
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Fe catalytic growth, microstructure, and low-threshold field emission properties of open ended tubular graphite cones. / Shang, NG; Papakonstantinou, P; McLaughlin, JAD; Chen, WC; Chen, LC; Chu, M; Stamboulis, A.

In: Journal of Applied Physics, Vol. 103, No. 12, 06.2008, p. 124308.

Research output: Contribution to journalArticle

TY - JOUR

T1 - Fe catalytic growth, microstructure, and low-threshold field emission properties of open ended tubular graphite cones

AU - Shang, NG

AU - Papakonstantinou, P

AU - McLaughlin, JAD

AU - Chen, WC

AU - Chen, LC

AU - Chu, M

AU - Stamboulis, A

PY - 2008/6

Y1 - 2008/6

N2 - Large-area tubular graphite cones (TGCs) with an open end were successfully synthesized on Si substrates by microwave plasma assisted chemical vapor deposition using a thin Fe film as catalyst. As-grown TGCs are uniformly distributed on the Si surface with a density of 5.8x10(5)/cm(2) and an average growth rate of 0.6 mu m/min. Some of them are very sharp with an apex angle as small as 2 degrees-3 degrees. Combined observations by transmission electron microscopy and cross-sectional scanning electron microscopy clarified that the TGCs possess a hollow nanotube core, a metal-free open tip and that the Fe catalyst is located in the root, strongly supporting the base-growth mechanism of TGCs. Scanning confocal micro-Raman spectroscopy along an individual TGC shows that the integrated intensity ratio of D to G band of individual TGC at tips (0.12) is an order of magnitude less than that at roots (1.2), confirming that the tip is highly crystalline whereas the root is of poor quality. Their field emission performance exhibits a turn-on field as low as 1.8 V/mu m and highly stable emission characteristics. The present study opens the way to site selective growth of TGCs and demonstrates its use as a potentially excellent emitter. (C) 2008 American Institute of Physics.

AB - Large-area tubular graphite cones (TGCs) with an open end were successfully synthesized on Si substrates by microwave plasma assisted chemical vapor deposition using a thin Fe film as catalyst. As-grown TGCs are uniformly distributed on the Si surface with a density of 5.8x10(5)/cm(2) and an average growth rate of 0.6 mu m/min. Some of them are very sharp with an apex angle as small as 2 degrees-3 degrees. Combined observations by transmission electron microscopy and cross-sectional scanning electron microscopy clarified that the TGCs possess a hollow nanotube core, a metal-free open tip and that the Fe catalyst is located in the root, strongly supporting the base-growth mechanism of TGCs. Scanning confocal micro-Raman spectroscopy along an individual TGC shows that the integrated intensity ratio of D to G band of individual TGC at tips (0.12) is an order of magnitude less than that at roots (1.2), confirming that the tip is highly crystalline whereas the root is of poor quality. Their field emission performance exhibits a turn-on field as low as 1.8 V/mu m and highly stable emission characteristics. The present study opens the way to site selective growth of TGCs and demonstrates its use as a potentially excellent emitter. (C) 2008 American Institute of Physics.

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