We grew vertically aligned carbon nanotubes (CNTs) using microwave plasma-enhanced (MPE) and thermal chemical-vapor deposition (CVD) and characterized their field emission properties. We observe that the flickering and instability in the field emission are due to the metal particles present on the field-emission array (FEA) surface, particularly from the MPECVD-grown samples. The existence of metal particles is an obstacle to obtaining reliable emission properties. The emission properties of the CNT–FEA are studied as a function of gas-exposure time with hydrogen, nitrogen, and oxygen gases. Gas exposures affected turn-on voltage, hysteresis, and the slope of Fowler–Nordheim plots. We observe that the saturation of emission currents is attributed to gas adsorbates present on the surface of the FEA. Oxygen exposures induce more severe degradation on the field-emission properties than nitrogen, whereas emission properties are improved by hydrogen gas exposures that clean the surface of emitters. In addition, hydrogenation of carbon nanotubes has technical importance for activation of the CNT–FEA.

1.
S.
Iijima
,
Nature (London)
354
,
56
(
1991
).
2.
P. G.
Collins
,
K.
Bradley
,
M.
Ishigami
, and
A.
Zettle
,
Science
287
,
1801
(
1997
).
3.
S. J.
Tans
,
M. H.
Devoret
,
H.
Dai
,
A.
Thess
,
R. E.
Smally
,
L. J.
Geerligs
, and
C.
Dekker
,
Nature (London)
386
,
474
(
1997
).
4.
N.
Choi
,
T.
Uchihashi
,
H.
Nishijima
,
T.
Ishida
,
W.
Mizutani
,
S.
Akita
, and
Y.
Nakayama
,
Jpn. J. Appl. Phys., Part 1
39
,
3707
(
2000
).
5.
P. G.
Collins
and
A.
Zettle
,
Appl. Phys. Lett.
69
,
1969
(
1996
).
6.
W. A.
De Heer
,
A.
Chatelain
, and
D.
Ugarte
,
Science
270
,
5239
(
1995
).
7.
W. B.
Choi
et al.,
Appl. Phys. Lett.
75
,
3129
(
1999
).
8.
P. R.
Schwoebel
and
I.
Brodie
,
J. Vac. Sci. Technol. B
13
,
1391
(
1995
).
9.
K. A.
Dean
and
B. R.
Chalamala
,
Appl. Phys. Lett.
75
,
3017
(
1999
).
10.
K. A.
Dean
and
B. R.
Chalamala
,
Appl. Phys. Lett.
76
,
375
(
2000
).
11.
J. P.
Bonard
,
J. P.
Salvetat
,
T.
Stockli
, and
W. A.
Heer
,
Appl. Phys. Lett.
73
,
918
(
1998
).
12.
Y. C.
Choi
,
Y. M.
Shin
,
Y. H.
Lee
,
B. Y.
Lee
,
G. S.
Park
,
W. B.
Choi
,
N. S.
Lee
, and
J. M.
Kim
,
Appl. Phys. Lett.
76
,
2367
(
2000
).
13.
C. J.
Lee
et al.,
Appl. Phys. Lett.
75
,
1721
(
1999
).
14.
P. G.
Collins
and
A.
Zettle
,
Phys. Rev. B
55
,
9391
(
1997
).
15.
J. M.
Macaulay
,
I.
Brodie
,
C. A.
Spindit
, and
C. E.
Holland
,
Appl. Phys. Lett.
61
,
997
(
1992
).
16.
J.
Liu
et al.,
Appl. Phys. Lett.
65
,
2842
(
1994
).
17.
J.
Liu
,
U. T.
Son
,
A. N.
Stepanova
,
K. N.
Christensen
,
G. J.
Wojak
,
E. I.
Givargizov
, and
J. J.
Hren
,
J. Vac. Sci. Technol. B
12
,
717
(
1994
).
18.
S. C. Lim et al. (unpublished).
19.
X. Y.
Zhu
,
S. M.
Lee
, and
T.
Frauenheim
,
Phys. Rev. Lett.
85
,
2757
(
2000
).
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