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Synthesis and optical properties of CuS
nanowires fabricated by electrodeposition
with anodic alumina membrane
Chien Wu a, Jen-Bin Shi b, Chih-Jung Chen a, Yu-Cheng Chen a, Ya-Ting
Lin a, Po-Feng Wu b, Sung-Yen Wei b
a The Graduate Institute of Electrical and Communications Engineering,
Feng-Chia University, Taichung 40724, Taiwan
b Department of Electronic Engineering, Feng-Chia University,
Taichung 40724, Taiwan
Received 7 June 2007; accepted 26 July 2007 Available online 1 August
2007
Advisor：S.C.Wang
Student：Shih-Kai Shu
Outline
 Introduction
 Experimental
Procedures
 Results and Discussion
 Conclusion
 Future work
Introduction
Metal nanowires are expected to be crucial components in
future nanoscale devices for chemical, mechanical,
electrical, magnetic, optical, and many other applications.
 During the past few years, considerable efforts have been
spent to develop viable methods for the fabrication of
metal nanowires.
 One-dimensional nanostructures have become the focus of
intense research, because they provide a good system for
investigating the dependence of electrical, optical, and
thermal transport or mechanical properties on
dimensionality and size confinement.
 As an important semiconductor material, copper sulfide
has been found many applications for its metallike
electrical conductivity, chemical-sensing capability and
ideal characteristics for solar energy absorption.

There are many ways to prepare nanosized copper
sulfide.
 Some methods, such as soft colloidal templates, in situ
template-controlled (ISTC) method, microwave
irradiation, template-free synthesis, biomolecule-assisted
hydrothermal approach, solid-state reaction route, have
been utilized to prepare one-dimensional CuS nanorods
and nanowires, searching for a simple synthetic route is
still an interesting subject worthy of further exploration.
 Herein we synthesize CuS nanowire by electrodepositing
with the template method, a way for preparing one
dimensional nanostructural materials, which entails
fabricating the desired material within the pores of a
template membrane.

The use of either direct current or alternate current for
the nanowire deposition of a range of materials (such as
CdSe, SnO2, TiO2, InO2, Bi2S3 etc) have already been
shown to produce well ordered crystallized highly dense
nanowire arrays.
 In this report, we use an AC and DC electrodeposition
process at the same time to fabricate CuS nanowire
arrays in AAM templates from a dimethylsulfoxide
(DMSO) solution containing copper chloride and
elemental sulfur.
 So far this is the first work to have successfully used
electrodeposition to fabricate aligned CuS nanowire
arrays and study its properties.

Experimental Procedures
Results and Discussion

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XRD was performed to analyze the
microstructure of the samples
(shown in Fig. 1).
In this measurement, we removed
the AAM from the CuS nanowire
arrays to avoid the effect of the
AAM.
When XRD pattern is compared
with that of the standard powder
diffraction pattern of CuS (JCPDS
79-2321) with hexagonal structure,
the intensity of peak (110) is higher
than other peaks, which is the
highest intensity in the standard
pattern, indicating that there was a
[110] preferred orientation during
the growth of the nanowires.
In XRD data, we didn‘t find any
phase about the elemental copper,
sulfur and Cu2S.

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
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Fig. 2(a)–(c) shows SEM images
of the ordered nanowires in an
anodic alumina membrane
template and the nanowire arrays.
SEM images show that the average
diameter of the pores is around 60
nm.
The nanowire arrays fill the
nanochannels uniformly and the
measured diameters of the
nanowires are equal to the pore
diameter.
Fig. 2 (d) shows EDS spectrum of
the CuS nanowire arrays without
AAM which verifies that the
nanowires consist of Cu and S, and
quantitative analysis of the
spectrum indicates that the atomic
ratio of Cu to S is close to 1:1.
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Fig. 3(a)–(d) show SEM images
of the ordered CuS nanowires
completely exposed after we
dissolved the AAM.
These spectrums show the
nanowires are obviously entire
and prolific.
There are two supposed steps
involving the electrodeposition
of CuS in the DMSO solution
containing CuCl2 and elemental
sulfur.
First, the elemental sulfur of the
solution diffuses to the electrode
surface, is absorbed on the
surface and then form in S2−
type.
Secondly, the generated S2− ions
react with the Cu2+ ion in the
solution to form CuS crystalline
core.
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In addition, we proposed an alternate and directcurrent process to
fabricate CuS nanowire arrays.
Because of the alternate-current process, the alternation of the electric
field will remove the undesired deposition that is deposited on the
surface of the AAM, and then influence the rate of the deposition.
For the direct-current process, the direction of the electric field makes
a high density deposition to form highly aligned ordered CuS
nanowire arrays.
Finally we considered the above reasons in which an AC with DC
method has successful produced highly quality CuS nanowire arrays.


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UV–Vis optical absorption
spectrum of CuS nanowires inside
the deionized water is shown in
Fig. 4.
The inset in Fig. 4 depicts the
energy scale of UV–Vis
absorption spectrum (0.5 eV to 7.5
eV) in proportion to its
wavelength.
The spectrum shows a strong
absorbance starts at around 550
nm, two absorption shoulders at
short wavelength 242 nm and 400
nm, and one broad absorbance
with a maximum at 825 nm in the
near-IR region.
Conclusion
In summary, the high density, uniform 60 nm CuS nanowire
arrays embedded in the pores of AAM template have been
prepared by an alternate with direct-current electrodeposition in dimethylsulfoxide (DMSO) solution
containing copper chloride and elemental sulfur.
 XRD and EDS present the microstructure of the CuS
nanowire.
 Spectra show the good crystalline with hexagonal structure
of the CuS nanowire arrays and almost a 1:1 composition
ratio.
 In UV analysis we suggested that the absorption peaks at
242 nm and 400 nm might be due to the characteristic of
Cu2S phase attributed from extreme few Cu2S composition
and the near-IR absorption peak at 825 nm might be due to
the characteristic of CuS phase attributed from major CuS
nanowires.

Future work
 Paper
review
 利用垂直基板和電化學沉積生成CuS奈米
線陣列，並於三月中進行FIB的作業。