Materials
Science
and
Engineering
B
178 (2013) 917–
922
Contents
lists
available
at
SciVerse
ScienceDirect
Materials
Science
and
Engineering
B
jou
rn
al
hom
ep
age:
www.elsevier.com/locate/mseb
Synthesis
and
photoluminescence
properties
of
Cl
−
-doped
ZnS
nanoparticles
prepared
by
a
solid-state
reaction
Xiao
Xia
Li
a
,
Zhong
Chen
b,∗
,
Guoping
Du
a
,
Nan
Chen
b
,
Quanmao
Yu
b
a
Institute
of
Functional
Materials,
Jiangxi
University
of
Finance
and
Economics,
Nanchang
330013,
PR
China
b
School
of
Materials
Science
and
Engineering,
Nanchang
University,
Nanchang
330031,
PR
China
a
r
t
i
c
l
e
i
n
f
o
Article
history:
Received
26
November
2012
Received
in
revised
form
2
May
2013
Accepted
9
May
2013
Available online 23 May 2013
Keywords:
Nanoparticles
Solid-state
reaction
Photoluminescence
Anneal
a
b
s
t
r
a
c
t
ZnS:Cl
−
nanoparticles
with
strong
blue
emission
have
been
synthesized
successfully
by
a
solid-state
reaction
at
low
temperature.
The
dependence
of
photoluminescence
(PL)
properties
of
ZnS:Cl
−
nanopar-
ticles
on
the
Cl
−
contents
was
researched,
and
the
influences
of
the
annealing
ambience
and
using
polyvinyl
alcohol
(PVA)
during
the
synthesis
on
the
PL
of
ZnS:Cl
−
(Cl/Zn
=
0.35)
nanoparticles
were
dis-
cussed.
X-ray
power
diffraction
(XRD),
X-ray
photoelectron
spectroscopy
(XPS),
transmission
electron
microscopy
(TEM),
and
ultraviolet-visible
spectroscopy
were
used
to
characterize
their
structure,
chem-
ical
state,
diameter,
surface
states,
and
PL
properties.
The
results
showed
that
ZnS:Cl
−
nanoparticles
had
a
cubic
blende
crystal
structure
and
an
average
crystallite
size
of
17.40–19.16
nm.
The
most
intensity
blue
emission
peaking
at
about
425
nm
was
obtained
when
Cl/Zn
=
0.35
under
330
nm
excitation
at
room
temperature.
The
emission
intensity
of
ZnS:Cl
−
(Cl/Zn
=
0.35)
was
increased
3-fold
than
that
of
ZnS.
The
results
showed
that
the
PL
of
ZnS:Cl
−
(Cl/Zn
=
0.35)
nanoparticles
was
enhanced
after
annealing
or
using
PVA
during
the
synthesis,
and
annealing
in
vacuum
had
a
stronger
effect
in
improving
the
luminescence
properties
of
ZnS
nanoparticles
than
in
air.
This
work
suggests
that
it
is
an
effective
method
to
improve
the
PL
intensity
of
ZnS
nanocrystals
by
doping
with
Cl
−
in
ZnS.
© 2013 Elsevier B.V. All rights reserved.
1.
Introduction
Zinc
sulfide
(ZnS),
a
wide
band-gap
semiconductor
with
a
band-
gap
energy
(E
g
)
of
3.68
eV
[1]
at
room
temperature,
is
one
of
the
most
typical
and
important
crystalline
materials
for
both
appli-
cation
and
research
[2–5].
Doped
ZnS
nanocrystals
have
attracted
more
attention
since
1994,
Bhargava
et
al.
[6]
reported
for
the
first
time
that
Mn
2+
doped
ZnS
nanosemiconductor
could
yield
both
high
quantum
luminescence
efficiency
and
lifetime
shortening
at
the
same
time.
The
results
suggested
that
doped
ZnS
nanocrystals
form
a
new
class
of
luminescent
materials,
which
have
a
wide
range
of
application
in
displays,
lighting,
sensors
and
lasers
[7–10].
Many
literatures
from
different
groups
have
reported
the
optical
proper-
ties
of
various
doped
ZnS
nanocrystals
and
the
potential
application
of
these
luminescent
materials
[11–19].
Although
the
previous
reports
focused
on
various
transition
metal
ions
and
rare-earth
ions
as
impurities
doped
or
co-doped
in
nanocrystalline
ZnS
host,
anions
have
also
been
found
to
be
effec-
tive
dopants
for
substituting
S
ions
in
ZnS
nanoparticles.
Yoshida
∗
Corresponding
author
at:
School
of
Materials
Science
and
Engineering,
Nan-
chang
University,
Nanchang
330013,
PR
China.
Tel.:
+86
791
83874867;
fax:
+86
791
83874867.
E-mail
address:
chenzhonglzu@sina.com
(Z.
Chen).
et
al.
[20]
reported
that
the
dissociation
of
F
from
TbF
3
in
the
ZnS
film
plays
an
important
role
in
obtaining
high
efficiency.
Okamoto
and
Watanabe
[21]
found
that
in
ZnS;TbF
x
thin
film
when
x
=
1,
this
ZnS:TbF
gave
high
electroluminescence
(EL)
efficiency.
Cor-
rado
et
al.
[22]
prepared
Cu
and
Br
co-doped
ZnS
nanocrystals
with
enhanced
luminescence
via
a
hot-injection
method.
Manzoor
et
al.
[23]
synthesized
ZnS
nanocrystals
codoped
with
halogen
ions
(F
−
,
Cl
−
,
Br
−
and
I
−
)
and
Cu
+
via
a
wet-chemical
precipitation
method.
In
their
work,
the
halogen
ions
were
supplied
by
ammonium
halogen
salts,
and
they
found
that
the
use
of
halogen
ions
as
co-activator
enhanced
the
emission
intensity.
Therefore,
it
is
worthy
of
more
detailed
studies
on
the
effect
of
incorporation
of
halogen
ions
on
the
PL
properties
of
ZnS
nanoparticles.
Especially,
both
Cl
−
and
S
2−
have
the
similar
ion
radius,
but
they
have
quite
different
electronegativity
ionradius.
Thus,
Cl
−
doping
in
ZnS
should
introduce
some
lattice
distortion
and
defects,
and
therefore
new
optical
and
electrical
properties
will
be
expected
for
the
Cl
−
-doped
ZnS
nanoparticles.
Hence
many
researches
on
micron-sized
and
bulk
ZnS
doped
with
Cl
−
or
codoped
with
Cl
−
and
cations
have
been
reported
[23–30],
and
it
has
been
found
that
Cl
−
doping
has
a
strong
effect
in
improving
the
luminescence
prop-
erties
of
ZnS
materials.
However,
less
attention
has
been
paid
to
Cl
−
-doped
nanosized
ZnS.
Besides
the
report
from
Manzoor
et
al.
[23]
as
stated
in
the
last
paragraph,
recently,
Yu
et
al.
[31]
also
observed
that
the
optoelectronic
properties
of
the
Cl
−
-doped
ZnS
0921-5107/$
–
see
front
matter ©
2013 Elsevier B.V. All rights reserved.
http://dx.doi.org/10.1016/j.mseb.2013.05.003
资源评论
