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Nano Research & Applications
ISSN: 2471-9838
April 26-27, 2018
Rome, Italy
NanoMat 2018
Page 38
17
th
Edition of International Conference on
Emerging Trends in
Materials Science and
Nanotechnology
L
arge reversible changes of the electronic transport properties
of solid-state oxide materials induced by electrochemical
fields have received much attention as a new research avenue
in iontronics. The action on time-dependence of conductive
modulation is slower. Despite the slow modulation, the
emergence of non-linear, plastic and/or memristive behaviors
provides an opportunity to obtain new abilities in information
processing, like signal flow in brain, in addition to sensing
and energy devices. In this conference, dramatic transport
changes in VO
2
nanowires were demonstrated by electric field-
induced hydrogenation at room temperature. As a suitable
device structure to perform transport modulation through
electrochemical reactions, we proposed a planar-type field effect
transistor with side gates and a nanowire channel separated by
air nanogaps (denoted PG-FET), as illustrated in Figure 1. This
unique structure allowed us to investigate hydrogen intercalation
and diffusion behavior in VO
2
channels with respect to both time
and space. Figure 2 shows the reversible, non-volatile resistance
changes in a VO
2
nanowire channel with a width (w) of 500 nm
obtained by applying positive and negative VG at 300 K under
a humidity of around 50%. The normalized resistance (R/R0,
where R and R0 are the measured resistance and resistance of
the pristine device before applying a VG at 300 K, respectively)
slowly decreased down to the saturation line at roughly
R/R
0
=
0.75 during the application of VG = +100 V. This state was held
after the removal of the VG. Namely, the device exhibited a non-
volatile memory effect. The
R/R
0
increased again with applying
V
G
= -100 V. Our results will contribute to further strategic
researches to examine fundamental chemical and physical
properties of devices and develop iontronic applications, as well
as offering new directions to explore emerging functions for
sensing, energy, and neuromorphologic devices combining ionic
and electronic behaviors in solid-state materials.
Recent Publications
1. MancaN, Pellegrino L, KankiT, VenstraWJ, Mattoni G,
Higuchi Y, Tanaka H, Caviglia A D and Marré D (2017)
Selective high-frequencymechanical actuation driven
by the VO
2
electronic instability. Advanced Materials
29, 1701618.
2. Wei T, Kanki T, Chikanari M, Uemura T, Sekitani T
and Tanaka H (2017) Enhanced electronic-transport
modulation in single-crystalline VO
2
nanowire-based
solid-state field-effect transistor. Scientific Reports 7,
17215.
3. Kanki T and Tanaka H (2017) Nanoscale
electrochemical transistors in correlated oxides. APL
Materials 5, 042303.
4. Wei T, Kanki T, Fujiwara K, Chikanari M and Tanaka H
(2016) Electric field-induced transport modulation in
VO
2
FETs with high-k oxide/organic parylene-C hybrid
gate dielectric. Applied Physical Letters 108, 053503.
5. Sasaki T, Ueda H, Kanki T and Tanaka H (2015)
Electrochemicalgating-induced reversible and drastic
resistance switching in VO
2
nanowires. Scientific
Reports doi: 10.1038/srep17080.
Room temperature hydrogenation in
functional oxide nanowires by an electric
field via air nanogap
Teruo Kanki
Institute of Scientific and Industrial Research - Osaka University, Japan
Teruo Kanki, Nano Res Appl, Volume:4
DOI: 10.21767/2471-9838-C1-007