Research Article
High Current-Induced Electron Redistribution in
a CVD-Grown Graphene Wide Constriction
Chiashain Chuang,
1
Tak-Pong Woo,
2,3
Fan-Hung Liu,
4
Masahiro Matsunaga,
1
Yuichi Ochiai,
1
Nobuyuki Aoki,
1
and Chi-Te Liang
2,4
1
Graduate School of Advanced Integration Science, Chiba University, Chiba 263-8522, Japan
2
Department of Physics, National Taiwan University, Taipei 106, Taiwan
3
Te Germination Program Ofce, Science & Technology Policy Research and Information Center, NARLabs, Taipei 106, Taiwan
4
Graduate Institute of Applied Physics, National Taiwan University, Taipei 106, Taiwan
Correspondence should be addressed to Tak-Pong Woo; bonwood@gmail.com, Nobuyuki Aoki; n-aoki@faculty.chiba-u.jp,
and Chi-Te Liang; ctliang@phys.ntu.edu.tw
Received 22 January 2016; Accepted 8 May 2016
Academic Editor: Yasuhiko Hayashi
Copyright © 2016 Chiashain Chuang et al. Tis is an open access article distributed under the Creative Commons Attribution
License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly
cited.
Investigating the charge transport behavior in one-dimensional quantum confned system such as the localized states and
interference efects due to the nanoscale grain boundaries and merged domains in wide chemical vapor deposition graphene
constriction is highly desirable since it would help to realize industrial graphene-based electronic device applications. Our data
suggests a crossover from interference coherent transport to carriers fushing into grain boundaries and merged domains when
increasing the current. Moreover, many-body fermionic carriers with disordered system in our case can be statistically described
by mean-feld Gross-Pitaevskii equation via a single wave function by means of the quantum hydrodynamic approximation. Te
novel numerical simulation method supports the experimental results and suggests that the extreme high barrier potential regions
on graphene from the grain boundaries and merged domains can be strongly afected by additional hot charges. Such interesting
results could pave the way for quantum transport device by supplying additional hot current to food into the grain boundaries and
merged domains in one-dimensional quantum confned CVD graphene, a great advantage for developing graphene-based coherent
electronic devices.
1. Introduction
Graphene, a single layer of carbon atoms arranged in a
hexagonal lattice, has demonstrated novel optoelectronic
and electronic devices in information technology, such as
photodetectors [1], solar cells [2, 3], and transistors [4].
Most importantly, the large-scale application of graphene
is an urgent development for industrial developments and
integrations. Te chemical vapor deposition (CVD) growth
of graphene has revealed great potential due to the large-
area, cost-efective, and industrial-like schemes such as
optical lithography to fabricate one-dimensional graphene
quantum constrictions for electronic coherent devices [5–
10]. Recent reports underscore the importance of interference
efects due to the intrinsic nanoscale grain boundaries and
merged domains within the CVD graphene [11, 12]. Such
nanoscale grain boundaries and merged domains revealed
diferent transport properties studied by low-temperature
scanning gate microscopy (LT-SGM) for making current
paths across that specifc regions [13, 14] so as to strongly
enhance the interference efect in comparison with homoge-
nous exfoliated graphene, like backscattering suppression
and Klein tunneling [15]. Such interesting CVD graphene-
based electronic devices with its intrinsic grain boundaries
and merged domains due to Aharonov-Bohm efect have
recently revealed interesting interference efect [14] and could
possibly fnely control and tune the total conductance by gate
voltages, magnetic felds, and source-drain currents so as to
generate a high on/of ratio signal as a quantum coherent
transistor for next generation information technology [16].
Hindawi Publishing Corporation
Journal of Nanomaterials
Volume 2016, Article ID 1806871, 7 pages
http://dx.doi.org/10.1155/2016/1806871