ORIGINAL PAPER
Phase transition properties of vanadium oxide films deposited
by polymer-assisted deposition
Fang Yue
•
Wanxia Huang
•
Qiwu Shi
•
Danxia Li
•
Yanyan Hu
•
Yang Xiao
•
Xianjing Deng
•
Cheng Wang
Received: 16 June 2014 / Accepted: 8 August 2014 / Published online: 19 August 2014
Ó Springer Science+Business Media New York 2014
Abstract Vanadium dioxide (VO
2
) films were synthe-
sized on mica substrates by a polymer-assisted deposition
method, followed by rapid annealing with different
annealing temperatures. The crystalline structure and
morphology of the films were investigated by XRD and
FE-SEM, and their phase transition properties were studied
by in situ FT-IR. The results indicated that the annealing
temperature affected the crystalline structure and mor-
phology of the films remarkably, which then resulted in
varied phase transition properties. In particular, the films
annealed at higher temperature showed more polycrystal-
line structure, increased particle size and reduced phase
transition intensity. But the films exhibited the similar
hysteresis temperature width with increasing annealing
temperature.
Keywords VO
2
film PAD Annealing temperature
Phase transition
1 Introduction
Vanadium can form various oxidation states, such as the
vanadium oxides of VO, V
2
O
3
,VO
2
,V
2
O
5
, and so on [1].
Among them, the VO
2
undergoes a first order metal–insu-
lator transition (MIT) around 340 K, from a low temperature
monoclinic semiconductor phase to a high temperature
tetragonal metal phase [2, 3]. The phase transition could also
be triggered by electric field, laser and stress, accompanied
by abrupt and dramatic chances in its electrical and optical
properties [4]. Moreover, the phase transition is reported to
occur at picosecond or even femtosecond scale [5]. Due to
these characteristics, the VO
2
has been widely studied and
applied in industrial and military field, such as but not limited
in thermochromic windows [6], switches [7], sensors [8] and
bolometer [9]. In particular, recent studies of VO
2
at tera-
hertz range open up huge potential for further applications
[10–12].
The VO
2
films have been deposited by different tech-
niques such as chemical vapor deposition [13], pulsed laser
deposition [14, 15], atomic layer deposition [16], sol–gel
[17] and chemical solution deposition (CSD). Among these
techniques, CSD offers an advantage a simple equipment
installation easy operation. The polymer-assisted deposi-
tion (PAD) [18, 19] is a developed CSD process. This
method could be used to grow metal-oxide films in large-
scale areas at low cost. This technique employs metal ions
coordinated to polymers as the film precursor [20]. The
polymer controls the viscosity of the solution and binds the
metal ions, resulting in a homogeneous precursor system
and the formation of uniform metal–organic films [21, 22].
The PAD method has some other advantages, such as but
not limited in better stability, accurately control of the
stoichiometry, applicable for deposition on flexible sub-
strate and flexible control of film thickness [23].
F. Yue W. Huang (&) Q. Shi D. Li Y. Hu Y. Xiao
College of Materials Science and Engineering, Sichuan
University, Chengdu 610064, Sichuan,
People’s Republic of China
e-mail: huangwanxiascu@aliyun.com;
huangwanxia@scu.edu.cn
Q. Shi (&)
College of Physical Science and Technology, Sichuan
University, Chengdu 610064, Sichuan,
People’s Republic of China
e-mail: shiqiwu_cd@aliyun.com
X. Deng C. Wang
Institute of Electronic Engineering, China Academy of
Engineering Physics, Mianyang 621900,
People’s Republic of China
123
J Sol-Gel Sci Technol (2014) 72:565–570
DOI 10.1007/s10971-014-3474-6