RESEARCH ARTICLE
Copyright © 2011 American Scientific Publishers
All rights reserved
Printed in the United States of America
Journal of
Nanoscience and Nanotechnology
Vol. 11, 1–4, 2011
Effects of the Host Morphologies on Luminescence
Properties of Nd
3+
-Doped LaF
3
Nanoparticles
Jiangbo She
1 2
, Chaoqi Hou
1 2
, Haitao Guo
1
, Chao Gao
1
,
Xiaoxia Cui
1
Min Lu
1
, Wei Wei
1 3 ∗
, and Bo Peng
1 3 ∗
1
State Key Laboratory of Transient Optics and Photonics, Xi’an Institute of Optics and Precision Mechanics,
Chinese Academy of Sciences Xi’an Shannxi, 710119, P.R. China
2
Graduate University of Chinese Academy of Science, Beijing 100039, P.R. China
3
Institute of Advanced Materials, Nanjing University of Posts and Telecommunications, Nanjing 210003, P.R. China
By using different surfactants, several host morphologies including rod-like, pot-like and shuttle-
like of LaF
3
:Nd
3+
(1% mol) nanoparticles were prepared by a simple microemulsion hydrother-
mal method, and their properties were characterised by XRD, TEM and photoluminescence
spectroscopy. The experimental results indicated that the rod-like and pot-like nanocrystals possess
well shaped hollow structures. The analysis of spectra proved that the local environment around the
dopant ion changed with the different host morphology, which in turn influenced the luminescence
properties. The luminescence lifetimes derived from biexponential fitting were 615 s (nanopots),
419 s (nanorods) and 194 s (nanoshuttles), respectively. This phenomenon is ascribed to the
weakening effect of hollow or fenestral structures to the nonradiative ratio.
Keywords:
Fluorescence, Nanostructures, Rare-Earth Fluorides, Morphologies.
1. INTRODUCTION
Rare-earth (RE) ions doped inorganic nanoparticles have
attracted more and more attention due to their sci-
entific interest and potential applications in solid-state
lasers,
1
display devices,
2
optical telecommunication
3
and
biolabels.
4
In which, the neodymium ion (Nd
3+
is one
of the most important dopants, because of its noninva-
sive excitation (808 nm) and luminescence (1060 nm)
which fall within the “water window” can easily pene-
trate tissue.
5
On the other hand, LaF
3
as a host matrix
has been received great interest because of its low vibra-
tion energies and superior optical transparency in the 200–
1100 nm region.
6
In recent years, many neodymium ions
doped LaF
3
nanoparticles were synthesized with different
morphologies and applications. As far as we know, much
work previously reported on neodymium ions doped LaF
3
nanoparticles emphasized the synthetic methodologies: co-
precipitation,
7
liquid–solid-solution (LSS),
8
and thermol-
ysis methods.
9
And, most of the nanoparticles are solid
sphere or block which were different only with the size
and morphology.
10 11
It still remains a challenge to set up
a facile method for growing high-quality nanocrystals in
∗
Authors to whom correspondence should be addressed.
terms of monodisperse, well shaped and hollow structural.
In contrast to solid nanoparticles, the hollow structural
nanoparticles can be expected to open new avenues in the
nanomaterials and offer new opportunities of a variety of
fields including biological labeling and imaging, chemi-
cal sensing, and drug delivery. Because of hollow struc-
tural nanoparticle can be considered as a unique irradiative
nanocontainer which will be easily tracked by detector.
Herein, the novel hollow structural LaF
3
:Nd
3+
(1% mol)
nanoparticles were synthesized by using a low-tempreture
microemulsion hydrothermal method. And the effects of
the surfactants both on the morphologies and on the lumi-
nescence properties were investigated in detail.
2. EXPERIMENTAL DETAILS
2.1. MATERIALS
All chemicals were used as received without further purifi-
cation. For the preparation of the microemulsions, com-
mercial Triton X-100, sodium dodecyl sulfate (Sigma), and
cetyltrimethylammonium bromide (Aldrich) were used as
surfactants. Analytical grade absolute ethanol and sodium
fluoride were obtained from Xi’an Chemical Corpora-
tion (Xi’an, China). Nd(NO
3
3
· 6H
2
O, La(NO
3
3
· 6H
2
O
(99.9%, Aldrich) were used as lanthanide sources.
J. Nanosci. Nanotechnol. 2011, Vol. 11, No. xx 1533-4880/2011/11/001/004 doi:10.1166/jnn.2011.4961 1