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Nano Research & Applications
ISSN 2471-9838 Advanced Nano 2017
Page 83
September 11-12, 2017 Amsterdam, Netherlands
20th International Conference on
Advanced Nanotechnology
Large single crystal graphene manufacture
James C Sung, Jian She Liu and Hai Chao Wang
Henan Graphene Synthetic Co., Ltd., China
Large single crystals of graphene were made by using
a solvent-catalyst of nickel metal. Both solid and liquid
processes were experimented with graphene single
crystals of mm demonstrated. The carbon so graphene
has phenomenal properties, such as with 100Xmechanical
strength of steel, 100X of electrical conductivity of
copper. However, these superb attributes belong to intact
honeycomb lattice (sp2) of carbon atoms. Unfortunately,
both natural andman-made graphene products are defects
ridden. They are also limited by the honeycomb size (la)
of carbon lattice. Hence, the graphene single crystals
available are nanometers across, such bacteria sized
graphene is best used as additives, such as strengthening
agent for polymers, or for corrosion retardant of coatings.
Although CVD methods claim to have large areas of
graphene deposition on metal foils (e.g. Cu), but the
bombardment of pyrolytic carbon atoms on substrate is
an irreversible (nonequilibrium) process, so most carbon
atoms may land in the wrong position and incapable to
move to the equilibrium sites. As a result, single crystals
with defects density commensurate to silicon wafer in the
order of 10 thousands per centimeter are also smaller than
one micron; like that those exfoliate from natural graphite.
The sublimation of SiC single crystal to form graphene
surface suffers the non-equilibrium process in reverse.
The reconstitution of remaining carbon atoms, although
nearby is kinetically slow at the sublimation temperature.
Consequently, the so called graphene wafer is not made,
and SiC single crystal wafer itself is expensive and source
may be solid or gas. For example, green house effected
carbonaceous gas could be used to strip carbon in
forming large crystals of graphite that would be a source
for making precious graphene.
Nano Research & Applications