Various type of graphene

Review
DOI: 10.1557/jmr.2019.377
This section of Journal of Materials Research is reserved for papers that are reviews of literature in a given area.
2D AND NANOMATERIALS
A review of graphene synthesis by indirect and direct
deposition methods
Yanxia Wu1,b)
, Shengxi Wang1
, Kyriakos Komvopoulos1,a)
1
Department of Mechanical Engineering, University of California, Berkeley, California 94720, USA
a)
Address all correspondence to this author. e-mail: kyriakos@me.berkeley.edu
b)
Permanent address: Institute of New Carbon Materials, Taiyuan University of Technology, Taiyuan 030024, China.
Received: 13 September 2019; accepted: 21 November 2019
The unique properties of graphene have led to the use of this allotrope of carbon in a wide range of
applications, including semiconductors, energy devices, diffusion barriers, heat spreaders, and protective
overcoats. The synthesis of graphene by process methods that either directly or indirectly rely on physical vapor
deposition, thermal annealing, laser irradiation, and ion/electron beam irradiation has drawn significant
attention in recent years, mainly because they can provide high purity, low temperature, high throughput, and
controllable growth of graphene on various substrates. This article provides a comprehensive assessment of
these methods by grouping them into two main categories, i.e., indirect methods in which a carbon layer is first
deposited on a substrate and then converted to graphene by some type of energetic post-treatment process
and direct methods in which graphene is directly synthesized on a substrate surface by a process that uses
a solid carbon source. The underlying growth mechanisms of these processes and the challenging issues that
need to be overcome before further advances in graphene synthesis can occur are interpreted in the context of
published results.
Introduction
The explosion of research dealing with two-dimensional
(2D) materials, such as graphene, has been fueled by their
novel material intricacies and the exploitation of their
unique electronic, mechanical, and optical properties. 2D
materials are layered structures of atomic- or nano-scale
thickness, which are used in various applications (e.g.,
semiconductors, electronics, sensors, energy storage devices,
photovoltaics, filters, and composite materials) due to their
unprecedented physical properties. Since 2D materials ex-
hibit the highest surface-to-volume ratio among all materi-
als, facile production of these materials can accelerate the
development of new approaches for tuning and improving
the surface characteristics of bulk materials and contribute to
the discovery of disruptive methods for assembling miniatur-
ized devices with novel functionalities and prolonged operation
lifetimes.
The field of 2D materials owes its establishment to the
discovery of graphene in 2004. Graphene consists of sp2
hybridized carbon atoms demonstrating hexagonal, Bernal, or
rhombohedral stacking [1], with partially filled p orbitals
existing above and below the graphene plane [2]. A graphitic
layer is known as single-layer graphene; 2–3 graphitic layers
stacked together are termed bilayer and trilayer graphene,
respectively; and 5–10 graphitic layers is generally referred
to as few-layer graphene, whereas a layered assembly of
about 20–30 graphitic layers is known as multilayer graph-
ene. Single-layer graphene usually exists in rippled form
and does not demonstrate any stacking, whereas few-layer
graphene may have several stacking arrangements, including
Bernal (ABAB), rhombohedral (ABCABC), and, less com-
monly, AAA stacking [3]. In few-layer graphene with no
discernible stacking (termed turbostratic), the interlayer space
(.0.342 nm) is larger than that of crystalline graphene
(0.335 nm). The electronic and magnetic properties of graphene
can be significantly affected by the presence of edges and steps
with zigzag motifs.
The properties of graphene are controlled by the number
and thickness of graphene layers and the density of defects
[4, 5, 6]. Because of its ultrathin thickness and unique nano-
structure, graphene can also act as an impermeable membrane
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to gas molecules as small as He [7]. As a single layer of carbon
atoms, graphene is ;100 times stronger than steel, demon-
strates extremely high specific surface area (with a theoretical
value of 2630 m2
/g), and is almost transparent. Furthermore,
graphene exhibits room-temperature thermal conductivity
twice that of diamond [8], extraordinary charge carrier mobility
(.200,000 cm2
/Vs) that makes it an excellent electrical conductor
[9], and ferromagnetic properties at room temperature [10].
Graphene demonstrates a high potential for use in a broad range
of contemporary applications, including electronic devices, energy
storage systems, and advanced composite materials [11], mainly
because of its remarkable electronic, magnetic, optical, thermal, and
mechanical properties (Table I) [8, 9, 12, 13, 14, 15, 16, 17, 18, 19].
Since the early studies dealing with the deposition of
graphene on a Pt crystal surface [20], the research interest on
graphene and its use in many applications have grown
significantly [21, 22, 23]. This has been aided by the
development of various methods for graphene fabrication,
such as precipitation from single-crystal transition metals
[1], mechanical exfoliation and cleavage [24], anodic bond-
ing [25], chemical exfoliation [26, 27], chemical vapor
deposition (CVD) [28], thermal decomposition of SiC [29],
and a few other methods [30]. The methods for synthesizing
graphene can be classified into several categories, depending
on the type of carbon source and the preparation method
(Fig. 1). For graphene precipitation, carbon can be deposited
on a single-crystal transition metal by CVD, physical vapor
deposition (PVD), spin coating, and laser ablation. The CVD
methods are sensitive to the film growth conditions (i.e.,
temperature, gas concentration, deposition time, and sub-
strate material), whereas the PVD methods provide high
purity, low temperature, high throughput, and controllable
growth of graphene on a wide range of substrate materials
[31, 32]. Depending on the energy source, PVD growth of
graphene can be achieved by vacuum evaporation, sputter
deposition, cathodic arc, ion plating, and ion beam–assisted
deposition (IBAD) (Fig. 2).
PVD-based fabrication of graphene can be accomplished by
direct deposition in a controlled environment using a high-
energy carbon source and a transition metal as the substrate or
by indirect deposition using a post-deposition treatment that can
convert an amorphous carbon (a-C) film to graphene (Fig. 3). In
the case of direct deposition, high-temperature graphene syn-
thesis can be realized in vacuum via the evaporation of a graphite
target by high-energy particle bombardment, leading to carbon
deposition onto a substrate consisting of a transition metal (or
alloy) attached to the cathode of the process chamber. The
energy for evaporation can be supplied by various methods, such
as pulsed laser deposition (PLD), ablation, and arc discharge.
The source product can be graphite, carbon nanotubes (CNTs),
C60 fullerene, a-C, or some other form of carbon. Tuning the
process conditions to promote the formation of graphene is fairly
complex and often empirical. In the case of indirect deposition,
the irregular crystal structure of a-C, which may also contain
crystal defects and a small amount of impurities, is thermody-
namically unstable with respect to graphite (DG , 0 for a-C to
graphite transformation); however, a-C transformation to graph-
ene is slow because it is kinetically stable. The phase change from
amorphous to crystalline carbon requires both high temperature
(.3027 °C) and high pressure. This is because the atomic
rearrangement in 2D and three-dimensional (3D) disordered
network structures necessitates the breakage of a very high
number of bonds for new bonds to form. However, only a small
fraction of a-C can be graphitized by this process [33]. This
problem can be remedied by using transition metals or alloys to
enhance the growth of graphene in a low-temperature/low-
pressure environment. The exact role of transition metals in
graphene synthesis has been interpreted in the context of various
processes, including dissolution precipitation, catalysis that lowers
the reaction barrier of a-C to graphene transformation [34], and
metal-induced crystallization. Although the exact growth process
is still under investigation, an intriguing common feature of the
foregoing indirect methods is the deposition of an a-C film
on a transition metal or alloy substrate and the subsequent
TABLE I: Physical and chemical properties of graphene.
Property Value Comparison with other materials Ref.
Young’s modulus 1.1 TPa . . . [12]
Tensile strength 125 GPa The specific strength is 100 greater than steel [12]
Electron mobilitya
2 105
cm2
/V s 140 higher than Si [9]
Thermal conductivitya
5 103
W/m K 10 higher than Cu [8, 13]
Light transmittance 97.7% Alternative to ITOb
and FTOc
films [14]
Surface area 2630 m2
/g 2 larger than CNTs [15, 16]
Oxidation temperature 450 °C . . . [17]
Permeability Impermeable to liquid/gases;
permeable to protons
The geometric pore size is smaller
than the diameter of He and H2
[18, 19]
a
Measured at 25 °C.
b
ITO 5 indium-tin oxide
c
FTO 5 flourine-doped tin oxide
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application of sufficiently high thermal or photonic energy to
convert a-C to graphene.
The objective of this article is to provide an appraisal of recent
advances in graphene synthesis by various indirect and direct
methods, such as PVD, thermal annealing, laser treatment, and
ion/electron beam irradiation, discuss associated graphene growth
mechanisms, and illuminate existing challenges that currently
inhibit the faster development of fabrication methods for graphene.
Indirect methods for graphene synthesis
Carbon film deposition
Carbon film deposition by most PVD techniques usually
involves a solid carbon target or carbon produced from a solid
source. Among various PVD methods of a-C film deposition,
the most common techniques are filtered cathodic vacuum arc
(FCVA) [35], sputtering [36], and pulsed laser-assisted deposition
[37, 38]. a-C films can be deposited on various substrates,
including dielectric materials [39] (e.g., Si, SiC, and SiO2) and
transition metals or alloys [40, 41]. The direct contact of an a-C
film with a transition metal (e.g., Fe, Ni, and Co) or alloy substrate
in metal (alloy)/a-C or a-C/metal (alloy) stacking configuration
reduces the energy barrier for a-C transformation to graphene
and improves the crystallinity of graphene [42].
The interaction between an a-C film and a metal (or alloy)
substrate plays a key role in the formation of graphene. The
carbon solubility (from a thermodynamics perspective) and the
carbon permeation (from a thermal kinetic perspective) are
critical factors affecting the growth of graphene on a metallic
substrate [43]. In the segregation process, both the solubility
and diffusion of carbon in the metal contribute to the growth
process of graphene [44, 45, 46]. Moreover, the metal affinity
for carbon can also influence the formation of graphene [47].
The concurrent occurrence of these effects can be interpreted
in the light of binary phase diagrams of transition metals and
carbon [48, 49]. For instance, according to the Ni–C phase
diagram, graphene growth mainly occurs in the Ni-graphite
phase, with no other phase existing at a temperature below
1455 °C. On the dissolution of carbon in the Ni at a temperature
above 1455 °C, nucleation and growth of graphene layers
commence at the Ni surface on the decrease of temperature.
Because the formation of metastable Ni3C promotes carbon
precipitation out of the Ni, a multilayer a-C film grows on the
Ni surface because carbon precipitation out of the Ni substrate
is a nonequilibrium process [50]. Alternatively, the Co–C and
Fe–C phase diagrams show carbon solubilities in the temper-
ature range of 850–1000 °C [51]. Co demonstrates a behavior
similar to that of Ni characterized by the separation of graphite
Figure 1: Synthesis of graphene by various methods classified based on the type of carbon source and preparation technique.
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from a pure metal during cooling. Due to the high affinity of Fe
and carbon for each other, a competition between the forma-
tion of graphitic carbon and iron carbide (Fe3C) is encountered
with the decrease in temperature. However, because Cu shows
little affinity for carbon, carbide formation does not commence
and the carbon solubility remains at a low level even at a high
temperature. Thus, it is difficult for Cu to convert a-C to
graphene as the temperature is decreased [34, 52, 53]. Conse-
quently, only single-layer or bilayer graphene formation can occur
on Cu even with CVD methods [54, 55]. Because the saturated
solubilities of carbon species in Cu and Ni are significantly
different and both metals do not form a carbide at a high
Figure 3: Conversion of graphite, CNTs, C60 fullerene, and a-C to graphene by sputtering, FCVA, evaporation, laser exfoliation, arc discharge, evaporation, plasma
etching, unzipping, annealing, PLD, and particle irradiation.
Figure 2: Synthesis of graphene by various PVD methods: (a) vacuum evaporation, (b) and (c) sputter evaporation, (d) FCVA, (e–g) ion plating, and (h) IBAD.
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temperature, the number of graphene layers can be tuned by
controlling the at.% and the structure of Cu–Ni alloys [56, 57, 58].
The formation of graphene on a metal surface can be
explained by the so-called catalyst theory [45] and metal-
induced crystallization [59]. The catalyst theory, which is
widely accepted for graphene synthesis by CVD, is based on
the catalytic effect of transition metals, resulting from their
ability to provide low-energy reaction pathways either by facile
changing of oxidation states or through the formation of
appropriate intermediates [47]. In view of the asymmetric
electron distribution in the d-shell (3d) of different metals, the
metal stability decreases in the order Cu . Ni . Co . Fe.
Therefore, Cu may be the most suitable catalyst for the
formation of graphitic carbon because it can stabilize carbon
at its surface through weak bonding, despite its low affinity for
carbon. This may explain the growth of single-layer graphene
by chemical adsorption catalyzed at the surface of a Cu
substrate. Other metal catalysts for graphene synthesis are Ta
and Ru. A thin layer of Ta carbide forms during the initial stage
of carbon deposition, which subsequently serves as the foun-
dation of graphene growth [18]. On the other hand, because Ru
does not form a carbide, graphene nucleation and growth
commence with the gradual decrease in temperature [60].
Metal-induced crystallization is similar to that of lowering
the crystallization temperature of amorphous semiconductors in
the presence of a metal [61]. This is known as metal-mediated or
metal-catalyzed crystallization and can be used to fabricate
mono- or polycrystalline materials by thermal annealing [62].
Briefly, carbon atoms diffusing into a metal layer at an elevated
temperature precipitate as graphene at the crystal surface,
reducing the lattice mismatch during cooling. The atomic
arrangement in the metal controls the growth of the crystal
lattice on atomic planes, defining the lattice orientation at the
crystal surface [63], which plays an important role in the growth
process of graphene. For most metals, the (111) crystal orienta-
tion is most favorable because it exhibits the lowest activation
energy and the least lattice mismatch with graphene [64, 65]. The
surface morphology (texture) of metals is another important
factor affecting the quality of graphene [66, 67]. Carbon
nucleation usually initiates at the sites of defects, such as
dislocations, grain boundaries, and kinks, exhibiting lower energy
barriers to graphene nucleation compared to a smooth surface
[68]. Therefore, the quality of graphene produced with single-
crystal catalysts is better than that produced from polycrystalline
catalysts that have more grain boundaries [63]. Different roles of
various metals in graphene nucleation and growth have been
postulated [69, 70], such as graphene growth on Ni by carbon
segregation or precipitation [28, 71] and graphene growth on Cu
by surface adsorption [72]. However, a clear consensus about the
growth mechanism of graphene on a metal surface by PVD-
based methods has not been established yet.
Although the type of metal greatly affects the formation of
graphene, the thickness of the a-C film and the metal layer play
equally important roles [73]. For example, experiments per-
formed with 2.5–40-nm-thick a-C films deposited on a SiO2/Si
substrate by electron beam evaporation and subsequently coated
with a 100–300-nm-thick Ni layer and annealed at 800 °C for
15 min revealed a linear variation of the graphene thickness with
the a-C film thickness [32]. In another annealing study of 0.15–
18-nm-thick a-C films deposited on a Ni/SiO2/Si substrate by
FCVA and then heated at 800 °C for 15 min in vacuum, the
thickness of the graphene layer measured after cooling was also
found to increase with the a-C film thickness, with single-layer
graphene attained with a 1-nm-thick a-C film [74].
Thermal annealing
A common process for inducing segregation of carbon impu-
rities from the bulk of a metal (or alloy) toward its surface is
thermal annealing [75]. This treatment is suitable for metals
and alloys with trace amounts of carbon species and provides
precise control of graphene growth. For instance, carbide
substrates and carbide films can be subjected to thermal
annealing to subsequently enhance the nucleation and growth
of graphene. Indeed, deposition of Ni on a SiC(001) single
crystal [76] or an a-Si/SiO2 substrate [77] has been used to
synthesize graphene by rapid thermal annealing. Another
approach to fabricate graphene is by high-temperature treat-
ment of a SiC substrate coated with a Co or Ni layer [78].
Because nickel silicide and cobalt silicide form at a high
temperature and decompose during rapid cooling, carbon is
released and a thin graphite layer grows on the substrate
surface [78, 79]. Graphene films of various thickness and
quality can be produced by controlling the thermal annealing
conditions, i.e., temperature, time, cooling rate, and atmo-
sphere [80, 81]. The annealing temperature affects carbon
segregation in the bulk of metals and, ultimately, the quality
of the grown graphene [75]. For fixed thermal conditions, the
graphene layer thickness increases with the annealing time. The
growth of graphene commences only when the temperature is
sufficiently low to allow carbon–carbon atom interaction. A
high cooling rate tends to produce large-area, few-layer
graphene, whereas a very high cooling rate is conducive to
the growth of bilayer graphene [63]. To prevent carbon
oxidation, thermal annealing is usually performed in vacuum
or reduced atmosphere. The successful synthesis of graphene
on a Cu/a-C/SiO2/Si substrate by annealing in H2 atmosphere
prompted researchers to argue that when a-C is used as a solid
carbon source, the growth mechanism of graphene in the
presence of a Cu catalyst differs from those of graphene grown
by CVD methods [36]. The foregoing synthesis of graphene
comprises the reduction of copper oxide by H2, the
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development of a high tensile stress in the Cu film formed after
prolonged annealing, the diffusion of H2 first through the Cu
film and subsequently into the underlying a-C for graphene
crystallization, and, finally, the formation and movement of
carbon radicals out of the Cu film [36].
An alternative annealing method is the so-called in situ
current-induced annealing. In this process, heating of an a-C
film deposited on an atomically clean graphene substrate causes
the small carbon clusters in the film to rearrange under the effect
of van der Waals force interaction with the graphene substrate
and to crystallize to graphene patches [83]. Moreover, localized
heating can modify graphene by introducing stresses, inducing
selective thinning of the graphene layer, and reducing the defect
density [84]. Table II summarizes the effect of thermal annealing
conditions on graphene synthesis by various PVD methods.
Combining PVD methods with thermal annealing to fabri-
cate graphene sheets is advantageous for four main reasons. First,
PVD deposition and annealing can be performed with a wide
range of substrate materials. Second, the annealing temperature
range is lower than that of traditional CVD methods. Third, these
indirect methods are highly repeatable, straightforward, and fairly
controllable. Fourth, the fabrication process can be tuned to
produce single-layer to multilayer graphene. The main disadvan-
tages of PVD-thermal annealing methods are the nonuniform
thickness of graphene resulting from the preferential growth of
graphene from defects and the need for vacuum, inert, or reduced
environments. In addition, the carbon–metal interaction and the
transformation processes leading to the formation of graphene
during thermal annealing require further investigation.
Laser methods
There are several laser methods for synthesizing graphene,
including laser exfoliation, intercalation and exfoliation in
liquid nitrogen, PLD, laser-induced ultrafast CVD, laser-
induced catalyst-free growth of graphene from solid carbon
sources, epitaxial graphene growth on a Si-rich surface of a SiC
substrate by laser sublimation of the surface Si atoms, reduction
of graphene oxide, and unzipping of CNTs [85] (Fig. 4). PLD is
commonly used to deposit graphene on various substrate
materials [86, 87] because it provides high growth rate, good
control over the thickness and morphology of graphene, and
low cost. PLD of graphene on a substrate, including graphite
and highly oriented pyrolytic graphite (HOPG), with or
without a metal layer involves the irradiation of a solid target
in high vacuum [88, 89] and can also be used as a post-process
treatment to selectively convert carbon to graphene. Laser
irradiation of a Ni/SiO2/Si substrate coated with an a-C film
leads to the adsorption of laser energy causing localized heating
of the Ni layer, subsequently instigating a-C to dissolve into the
Ni, with the retraction of the Ni layer indicating the formation
of graphene over the laser-irradiated area of the substrate [90].
TABLE II: Synthesis of graphene under different annealing conditions by various PVD methods.
Method
Metal
species
Film/
substrate
a-C film
thickness (nm)
Metal
thickness
(nm)
Atmosphere,
pressure (mTorr)
Temperature
(o
C)
Time
(min)
Cooling rate
(o
C/min)
Graphene
typea
Ref.
Sputtering Cu Cu/a-C/
SiO2/Si
12, 36, 60 800 H2
1020 20, 50 . . . ML [36]
920 20, 30 . . . SL, FL (3–9) [36]
Co Co/6H–SiC . . . . . . Vacuum, Ar, air 900–1000 . . . Fast (water
bath)
SL to ML [78]
Ni a-C/Ni/
dielectric
5 65 20 1100 2 60 Controlled [40]
Electron beam
evaporation
M 5 Ni, Co M/a-C/
SiO2/Si
2.5–40 100–300 Ar, 1700 650–900 15 1200 ML [26]
Cu–Ni Cu/Ni–Cu/
SiO2
. . . 10–130, 370 Vacuum 900 . . . 2–4 SL to FL [56]
Ni Ni/6H–SiC . . . 200 104
;750 . . . 10–20 SL to FL [76]
Ni/3C–SiC/Si
FCVA Ni a-C/Ni/
SiO2/Si
1, 2, 3, 6, 10, 18 300 Vacuum 800 15 Natural SL to ML [39]
Ni a-C/Ni/
SiO2/Si
1–50 300 Vacuum 600–1000 5 50 FL [81]
Laser ablation Ni a-C/Ni/Si 5 150 7.5 104
780 45 Natural FL [82]
PLD Ni a-C/Ni/Si . . . 500 103
1100, 1200,
1300
. . . 1, 30 FL [37]
M 5 Ni, Cu,
Co, Fe
a-C/M ;7 500–600 3.75 103
750 1.5 1, 20 FL [44]
Sn C/Sn/a-C/
SiO2/Si
50 500 3.75 104
250 . . . . . . ML [31]
a
SL 5 single layer, FL 5 few layer, ML 5 multilayer.
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Laser flash synthesis of graphene is another indirect
method. For example, graphene can be fabricated on silicon
and quartz substrates with this method using a solid carbon
source, e.g., polymethyl methacrylate (PMMA). The associated
mechanism comprises the sequential processes of the dissociation
of solid carbon source into carbon atoms, the dissolution of
carbon atoms into the generated molten pool of silicon or quartz,
and the diffusion of carbon atoms back to the surface, leading to
the formation of graphene lattice upon cooling [85]. Because the
thickness of PLD-deposited graphene increases with the laser
ablation time, less carbon deposition and/or a thicker Ni film are
needed to produce few-layer graphene (#5 layers) [91]. When
considering graphene synthesis by the PLD technique, the
formation of 4–5 graphene layers requires a substrate temperature
of 700 °C, whereas the formation of multilayer graphene occurs at
a lower substrate temperature in the range of ;25–500 °C [92].
Selective graphitization of SiC and epitaxial graphene growth can
be achieved by integrating PLD with ion implantation [93].
Unlike the PVD-thermal annealing indirect methods that
are usually performed in vacuum, PLD-assisted synthesis of graph-
ene can be performed in ultrahigh vacuum, liquid, or ambient
conditions and is applicable to a wide range of materials, in
particular, materials with chemically active surfaces. Moreover,
the fabrication of graphene by PLD is fast (of the order of a few
microseconds) and the thickness of the produced graphene
sheets is relatively uniform. However, this method has also
some drawbacks, such as a small fabrication size (up to ;1 cm)
[86], the growth of a mixture of single-layer, bilayer, trilayer,
few-layer, and multilayer graphene sheets, and the limited
insight into the fundamental physics of the growth processes.
Energetic particle irradiation
Ion beam irradiation is an effective PVD method for inducing
rapid nonthermal phase transformation. The stopping of
electrons by carbon atoms provides the energy for phase
transformation during ion bombardment [94]. Low-energy
ion beam treatment produces point defects and enhances
diffusion, causing a-C to crystallize to graphene in the upper
region of the ion bombarded a-C film [95]. Electron beam
irradiation at 80 kV of an a-C film deposited on graphene or
h-BN membranes causes transformation to graphene layers
that form parallel to the support material due to the effect of
van der Waals force interaction among the graphene layers
[96]. Electron beam irradiation can also convert an a-C film to
spherical graphene or sp2
carbon onions selectively [97, 98].
Energetic particle irradiation requires highly specialized
equipment, and graphene synthesis by ion and electron beam
irradiation techniques is relatively sparse. In fact, energetic
particle irradiation is mostly used to modify the graphene
structure by introducing a certain type of defects or to section
the graphene sheets. A phase change from a-C to graphitic
carbon can also be induced by a high-temperature/high-
pressure treatment resulting in extensive graphitization [99].
This treatment is a two-stage transition process comprising the
formation of turbostratic carbon layers in the temperature
range of 600–900 °C, followed by atom rearrangement within
Figure 4: Synthesis of graphene by various laser methods. Graphene formation by (a) pulsed-laser sputtering of a graphite target, (b) laser-induced conversion of
a-C to graphene, (c) laser-assisted SiC decomposition, (d) laser-assisted CH4 decomposition, (e) CNT unzipping with a laser, (f) laser exfoliation, (g) graphene oxide
reduction with a laser, and (h) laser-assisted decomposition of PMMA.
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the carbon layers at a higher temperature, resulting in the
formation of graphitic sheets and 3D ordering [100].
In general, the indirect methods used to synthesize graph-
ene are controllable and low cost. Since the a-C film and
metal layers can be easily deposited on most substrate materials
by various PVD methods, the size and shape of the fabricated
graphene mainly depend on the substrate. The post-process
(i.e., thermal annealing or PLD) used to transform a-C to
graphene requires an environment of moderate temperature
and low pressure. Although the indirect methods discussed
above have provided effective means of producing various
types of graphene, there are still some challenges that must be
overcome, such as sample preparation, nonuniform thickness
of graphene layer, small area of coverage, and low yield. In
addition, more fundamental studies should be performed to
elucidate the effects of several important factors affecting the
quality and thickness of the graphene layer, such as carbon–
metal interaction during a-C film deposition and the mecha-
nism controlling a-C to graphene transformation. Table III
shows a comparison of the indirect methods of graphene
synthesis discussed in “Indirect methods for graphene synthe-
sis” section.
Direct methods for graphene synthesis
Arc discharge
Arc discharge, a phenomenon encountered when direct current is
passed between two high-purity graphite electrodes, has been
widely used to fabricate carbon nanomaterials, such as fullerenes
and CNTs. This method can be also used to controllably
synthesize high-purity graphene. For example, graphene flakes
have been fabricated by arc discharging in relatively high-
pressure hydrogen ambient without the need of a catalyst
[101]. Few-layer graphene has been synthesized by the arc
discharge method using different buffer gases [102]. The presence
of hydrogen gas in the buffer is important because it terminates
the dangling bonds of carbon, thus inhibiting rolling-up and
closing of the graphitic sheets, whereas a treatment with a He/H2
gas mixture produces graphene of high crystallinity [103].
Although arc discharging can be performed in air, it
requires a high working pressure. Furthermore, the small
number of graphene sheets produced by this method are often
crumpled, loosely stacked, or randomly aggregated, which
increases the distance between the graphene sheets. The former
effect in conjunction with the smaller size of the aggregated
graphene particles compared to that of the graphite powder
contribute to the increase of the surface area of graphene
particles [103]. However, the cost of this method is low and can
be used to deposit graphene over a large surface area.
Consequently, the main challenge with arc discharging is the
fabrication of low defect density graphene.
Laser methods
Among various laser methods for directly synthesizing graph-
ene from a-C, the most often used techniques are laser
exfoliation (either ablation or exfoliation of graphite flakes)
and PLD. Laser exfoliation can be used to dehydrogenate or
catalyze the removal of halogen from a graphene surface and to
detach either a portion or the whole graphene layer [104].
Carbon clusters of various sizes form on the irradiated graphite
surface during laser ablation. By placing the laser focal point at
the graphite surface and controlling other important process
parameters (i.e., laser energy, ablation volume, focal length,
background gas, working pressure, and target–substrate dis-
tance), the graphite can be evaporated in the form of carbon
nanoparticles, which then restructure into a thin graphene
layer at the substrate surface. Graphitic and sp3
carbon can be
converted to good-quality, graphene-like structures by laser
exfoliation even under atmospheric conditions [105]. However,
controllable transformation of carbon materials to graphene by
laser methods is challenging and requires inert or vacuum
environments [106].
As mentioned earlier, laser exfoliation can be used to
directly convert solid carbon-containing materials (e.g., SiC,
PMMA, and polyimide sheets) to graphene without resorting
to transition metal catalysts and/or templates. Ultraviolet laser
processing can be employed to directly deposit nanostructured
graphene films onto various substrates without the need of
a catalyst [107]. Additionally, graphene growth can be achieved
by ultrashort pulsed laser irradiation of a graphite target in
ultrahigh vacuum using a transition metal as the substrate [62].
In the foregoing process, graphene grows directly on the
transition metal at a high temperature without the formation
of carbide at the graphene/metal interface, and the thickness of
TABLE III: Comparison of various indirect methods for graphene synthesis.
Indirect method Area coverage Controllable Cost Yield Environmentally benign
Thermal annealing Large Relatively easy Low High Yes
Laser methods Large Relatively easy Low Relatively low Yes
Ion beam irradiation Small Relatively easy Relatively high Relatively low Yes
Electron beam irradiation Small Relatively easy Relatively high Relatively low Yes
Energetic particle irradiation Small Relatively easy Relatively high Relatively low Yes
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the graphene layer can be accurately modulated by tuning the
laser fluence, substrate temperature, and ablation time. Direct
deposition of graphene on a Ni substrate can also be performed
with an excimer laser for a substrate temperature in the range
of 1100–1300 °C [37]. The carbon solubility and cooling rate
play important roles in the growth of graphene on Ni, Cu, Co,
and Fe substrates by the PLD method [44]. Investigations of
graphene layer deposition on fused silica by PLD in oxygen
ambient showed the formation of randomly oriented, folded,
and disordered graphene at room temperature and the growth
of few-layer graphene exhibiting high crystallinity at 700 °C
[92]. Moreover, heating of a Si(100) substrate previously PLD-
coated with a hydrogenated a-C film was found to induce a-C
transformation to hydrogenated graphene [108]. Precipitation
of few-layer graphene exhibiting low defect density has been
reported for ,100 mJ pulsed laser energy and 50 °C/min
cooling rate [109]. Fabrication of free-standing 2D few-layer
graphene in liquid nitrogen has been achieved by laser
exfoliation of HOPG using pulsed nanosecond laser ablation
performed with a Q-switched Nd:YAG laser of 1064 nm
wavelength [110].
The fabrication of graphene by laser exfoliation has several
advantages, including relatively low process temperature, good
adhesion to the substrate, and high growth rate [86]. This
single-step (direct) process is significantly faster than most
other contemporary techniques, and because it involves clean
synthesis by optical excitation, the chemical impurities are
minimal. However, as with the PLD method, the main
challenge is the nonuniform thickness of the fabricated
graphene layers.
Other direct methods
Another direct method for synthesizing graphene is by the
rapid evaporation of bulk carbon onto heated Ni foils in
a vacuum evaporator using spectroscopically pure graphite
rods as electrodes [111]. Single-layer graphene sheets can be
fabricated by an ultrafast growth process, referred to as
magnetic-filtered, high-current arc evaporation, which uses
a graphite carbon source, a Cu substrate preheated in H2,
and cooling in Ar/H2 atmosphere [112]. Multilayer graphene
films can be grown on Cu and Ni substrates at a moderate
temperature by energetic PVD [113]. Large-area, high-quality,
single-layer graphene can be deposited on Cu foils at relatively
low temperatures by C60 molecule evaporation in ultrahigh
vacuum [114]. Graphite etching by H2O2 plasma is another
direct method for growing few-layer graphene [115].
CNTs can be used to fabricate thin elongated strips of
graphene. In this technique, double-walled CNTs are synthe-
sized by a multi-step process comprising double-walled CNT
unzipping by introducing defects via annealing at 500 °C,
dispersion of the double-walled CNTs in an organic solution,
sonication, and peeling off in two single-layer graphene nano-
ribbons (GNRs), and, finally, purification by a high-speed
centrifuge resulting in the conversion of more than 99% of
the produced GNRs to single-layer GNRs [116]. Because the
unzipping process produces high-quality CNTs, it is suitable
for most demanding electronic applications. The dimensions of
the graphene sheets produced by this method depend on the
density and size of CNTs. Thus, the width and thickness of the
fabricated graphene depend on the diameter and number of
CNTs, respectively, which is difficult to control at large scales.
Furthermore, the fabrication of CNTs requires further work to
improve the quality and process yield. Thus, large-scale
graphene fabrication by this method is challenging. A major
drawback with the direct methods discussed in this subsection
is the relatively low growth rate.
Table IV shows a comparison of the direct methods of
graphene synthesis discussed in “Direct methods for graphene
synthesis” section. Different from the indirect methods, graph-
ene fabrication with direct methods requires only one process
chamber or a single environment and is relatively easier to
implement, which simplifies the manufacturing protocol.
However, fabrication at elevated temperatures, high pressures,
and strong reducing media is a disadvantage.
Concluding remarks and future challenges
The unique properties of graphene make this allotrope of
carbon highly desirable for a wide range of applications.
However, despite of many methods available for fabricating
graphene, large-scale, low-cost, high-yield production of low-
defect graphene under environmentally benign process con-
ditions is still challenging. Indirect methods have attracted
great attention in recent years, particularly methods that use
carbon deposition processes, followed by the conversion of
carbon to graphene by some type of energetic treatment, such
as PVD techniques, thermal annealing, laser treatment, and
ion/electron beam irradiation. These methods are fairly con-
trollable and can be used to synthesize graphene on top of
different substrate materials (e.g., metals, glass, and ceramics)
TABLE IV: Comparison of various direct methods for graphene synthesis.
Direct
method
Area
coverage Controllable Cost Yield
Environmentally
benign
Arc
discharge
Large Relatively
easy
Low High Yes
Laser
methods
Large Relatively
easy
Low High Yes
Evaporation Large Relatively
easy
Low Relatively
low
Yes
Unzipping Small Relatively
hard
Low Relatively
low
No
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in rather mild environments. These indirect methods rely on the
fact that a-C is thermodynamically unstable with respect to
graphite (DG , 0 for a-C transformation to graphite), although
a-C transformation to graphene is slow because it is kinetically
stable. Nevertheless, the formation of high-purity graphene at low
temperatures and pressures is still under investigation. Although
direct methods use various carbon sources and are simpler than
indirect methods, they provide limited control over the size,
crystallinity, phase composition, and distribution of graphene.
There are several key issues that need to be addressed before
further advancements can occur in this field. First, the relation-
ship between the sp3
carbon content and the transformation
from sp3
carbon to good-quality graphene must be better
understood. Second, the carbon–metal interactions encountered
with different processes (e.g., deposition and phase transforma-
tion) require further in-depth study. Third, more studies must be
devoted on identifying the actual role of the substrate material,
carbon layer thickness, stacking configuration, and post-process
(e.g., annealing or irradiation) parameters on the growth process
of various types of graphene. Fourth, the nucleation and growth
mechanisms and structure–property relations of graphene are
still under investigation. Fifth, there is a need to further advance
the efficiency of microanalysis techniques currently used to
analyze the nanostructure, composition, physical properties,
and quality of 2D materials, such as graphene.
Acknowledgments
This work was partially supported by Western Digital
Technologies, Inc. The first author acknowledges the financial
support provided by the China Scholarship Council in the form
of a scholarship.
References
1. W. Choi, I. Lahiri, R. Seelaboyina, and Y.S. Kang: Synthesis of
graphene and its applications: A review. Crit. Rev. Solid State
Mater. Sci. 35, 52 (2010).
2. R.S. Edwards and K.S. Coleman: Graphene synthesis:
Relationship to applications. Nanoscale 5, 38 (2013).
3. K.F. Mak, J. Shan, and T.F. Heinz: Electronic structure of few-
layer graphene: Experimental demonstration of strong dependence
on stacking sequence. Phys. Rev. Lett. 104, 176404 (2010).
4. F. Miao, S. Wijeratne, Y. Zhang, U.C. Coskun, W. Bao, and
C.N. Lau: Phase-coherent transport in graphene quantum
billiards. Science 317, 1530 (2007).
5. S. Adam, E.H. Hwang, E. Rossi, and S. Das Sarma: Theory of
charged impurity scattering in two dimensional graphene. Solid
State Commun. 149, 1072 (2009).
6. H.S. Skulason, P.E. Gaskell, and T. Szkopek: Optical reflection
and transmission properties of exfoliated graphite from
a graphene monolayer to several hundred graphene layers.
Nanotechnology 21, 295709 (2010).
7. J.S. Bunch, S.S. Verbridge, J.S. Alden, A.M. van der Zande,
J.M. Parpia, H.G. Craighead, and P.L. McEuen: Impermeable
atomic membranes from graphene sheets. Nano Lett. 8, 2458 (2008).
8. A.A. Balandin, S. Ghosh, W. Bao, I. Calizo, D. Teweldebrhan,
F. Miao, and C.N. Lau: Superior thermal conductivity of single-
layer graphene. Nano Lett. 8, 902 (2008).
9. K.I. Bolotin, K.J. Sikes, Z. Jiang, M. Klima, G. Fudenberg,
J. Hone, P. Kim, and H.L. Stormer: Ultrahigh electron mobility
in suspended graphene. Solid State Commun. 146, 351 (2008).
10. Y. Wang, Y. Huang, Y. Song, X. Zhang, Y. Ma, J. Liang, and
Y. Chen: Room-temperature ferromagnetism of graphene. Nano
Lett. 9, 220 (2009).
11. Y. Zhu, S. Murali, W. Cai, X. Li, J.W. Suk, J.R. Potts, and
R.S. Ruoff: Graphene and graphene oxide: Synthesis, properties,
and applications. Adv. Mater. 22, 3906 (2010).
12. C. Lee, X. Wei, J.W. Kysar, and J. Hone: Measurement of the
elastic properties and intrinsic strength of monolayer graphene.
Science 321, 385 (2008).
13. S. Ghosh, I. Calizo, D. Teweldebrhan, E.P. Pokatilov,
D.L. Nika, A.A. Balandin, W. Bao, F. Miao, and C.N. Lau:
Extremely high thermal conductivity of graphene: Prospects for
thermal management applications in nanoelectronic circuits.
Appl. Phys. Lett. 92, 151911 (2008).
14. R.R. Nair, P. Blake, A.N. Grigorenko, K.S. Novoselov,
T.J. Booth, T. Stauber, N.M.R. Peres, and A.K. Geim: Fine
structure constant defines visual transparency of graphene.
Science 320, 1308 (2008).
15. M.D. Stoller, S. Park, Y. Zhu, J. An, and R.S. Ruoff: Graphene-
based ultracapacitors. Nano Lett. 8, 3498 (2008).
16. F. Schedin, A.K. Geim, S.V. Morozov, E.W. Hill, P. Blake,
M.I. Katsnelson, and K.S. Novoselov: Detection of individual gas
molecules adsorbed on graphene. Nat. Mater. 6, 652 (2007).
17. L. Liu, S. Ryu, M.R. Tomasik, E. Stolyarova, N. Jung,
M.S. Hybertsen, M.L. Steigerwald, L.E. Brus, and G.W. Flynn:
Graphene oxidation: Thickness-dependent etching and strong
chemical doping. Nano Lett. 8, 1965 (2008).
18. V. Berry: Impermeability of graphene and its applications.
Carbon 62, 1 (2013).
19. W. Yuan, J. Chen, and G. Shi: Nanoporous graphene materials.
Mater. Today 17, 77 (2014).
20. B. Lang: A LEED study of the deposition of carbon on platinum
crystal surfaces. Surf. Sci. 53, 317 (1975).
21. E. Rokuta, Y. Hasegawa, A. Itoh, K. Yamashita, T. Tanaka,
S. Otani, and C. Oshima: Vibrational spectra of the monolayer
films of hexagonal boron nitride and graphite on faceted Ni(755).
Surf. Sci. 427–428, 97 (1999).
22. K.S. Novoselov, A.K. Geim, S.V. Morozov, D. Jiang, Y. Zhang,
S.V. Dubonos, I.V. Grigorieva, and A.A. Firsov: Electric field
effect in atomically thin carbon films. Science 306, 666 (2004).
Review
j
Journal
of
Materials
Research
j
Volume
35
j
Issue
1
j
Jan
14,
2020
j
www.mrs.org/jmr
Downloaded
from
University
of
Nebraska
Lincoln,
on
14
Jan
2020
at
13:14:10,
subject
to
the
Cambridge
Core
terms
of
use,
available
at
https://doi.org/10.1557/jmr.2019.377

23. H. Shioyama: Cleavage of graphite to graphene. J. Mater. Sci.
Lett. 20, 499 (2001).
24. K.S. Novoselov, D. Jiang, F. Schedin, T.J. Booth,
V.V. Khotkevich, S.V. Morozov, and A.K. Geim: Two-
dimensional atomic crystals. Proc. Natl. Acad. Sci. U. S. A. 102,
10451 (2005).
25. T. Moldt, A. Eckmann, P. Klar, S.V. Morozov, A.A. Zhukov,
K.S. Novoselov, and C. Casiraghi: High-yield production and
transfer of graphene flakes obtained by anodic bonding. ACS
Nano 5, 7700 (2011).
26. S. Stankovich, D.A. Dikin, R.D. Piner, K.A. Kohlhaas,
A. Kleinhammes, Y. Jia, Y. Wu, S.T. Nguyen, and R.S. Ruoff:
Synthesis of graphene-based nanosheets via chemical reduction
of exfoliated graphite oxide. Carbon 45, 1558 (2007).
27. Y. Hernandez, V. Nicolosi, M. Lotya, F.M. Blighe, Z. Sun,
S. De, I.T. McGovern, B. Holland, M. Byrne, Y. Gun’ko,
J. Boland, P. Niraj, G. Deusberg, S. Krishnamurti, R. Goodhue,
J. Hutchison, V. Scardaci, A.C. Ferrari, and J.N. Coleman:
High yield production of graphene by liquid phase exfoliation of
graphite. Nat. Nanotechnol. 3, 563 (2008).
28. A. Reina, X. Jia, J. Ho, D. Nezich, H. Son, V. Bulovic,
M.S. Dresselhaus, and J. Kong: Large area, few-layer graphene
films on arbitrary substrates by chemical vapor deposition. Nano
Lett. 9, 30 (2009).
29. Y.Q. Wu, P.D. Ye, M.A. Capano, Y. Xuan, Y. Sui, M. Qi,
J.A. Cooper, T. Shen, D. Pandey, G. Prakash, and
R. Reifenberger: Top-gated graphene field-effect-transistors formed
by decomposition of SiC. Appl. Phys. Lett. 92, 092102 (2008).
30. M.S.A. Bhuyan, M.N. Uddin, M.M. Islam, F.A. Bipasha, and
S.S. Hossain: Synthesis of graphene. Int. Nano Lett. 6, 65 (2016).
31. R. Vishwakarma, M.S. Rosmi, K. Takahashi, Y. Wakamatsu,
Y. Yaakob, M.I. Araby, G. Kalita, M. Kitazawa, and
M. Tanemura: Transfer free graphene growth on SiO2 substrate
at 250 °C. Sci. Rep. 7, 43756 (2017).
32. M. Zheng, K. Takei, B. Hsia, H. Fang, X. Zhang, N. Ferralis,
H. Ko, Y-L. Chueh, Y. Zhang, R. Maboudian, and A. Javey:
Metal-catalyzed crystallization of amorphous carbon to graphene.
Appl. Phys. Lett. 96, 063110 (2010).
33. J. Peng, N. Chen, R. He, Z. Wang, S. Dai, and X. Jin:
Electrochemically driven transformation of amorphous carbons
to crystalline graphite nanoflakes: A facile and mild
graphitization method. Angew. Chem. 129, 1777 (2017).
34. J.A. Rodríguez-Manzo, C. Pham-Huu, and F. Banhart:
Graphene growth by a metal-catalyzed solid-state transformation
of amorphous carbon. ACS Nano 5, 1529 (2011).
35. G.A.J. Amaratunga, M. Chhowalla, C.J. Kiely, I. Alexandrou,
R. Aharonov, and R.M. Devenish: Hard elastic carbon thin films
from linking of carbon nanoparticles. Nature 383, 321 (1996).
36. U. Narula, C.M. Tan, and C.S. Lai: Growth mechanism for low
temperature PVD graphene synthesis on copper using
amorphous carbon. Sci. Rep. 7, 44112 (2017).
37. H. Zhang and P.X. Feng: Fabrication and characterization of
few-layer graphene. Carbon 48, 359 (2010).
38. C. Maddi, F. Bourquard, V. Barnier, J. Avila, M-C. Asensio,
T. Tite, C. Donnet, and F. Garrelie: Nano-architecture of
nitrogen-doped graphene films synthesized from a solid CN
source. Sci. Rep. 8, 3247 (2018).
39. A.K. Kesarwani, O.S. Panwar, S.R. Dhakate, V.N. Singh,
R.K. Rakshit, A. Bisht, and A. Kumar: Determining the number
of layers in graphene films synthesized by filtered cathodic vacuum
arc technique. Fuller. Nanotub. Car. Nanostruct. 24, 725 (2016).
40. W. Xiong, Y.S. Zhou, L.J. Jiang, A. Sarkar, M. Mahjouri-
Samani, Z.Q. Xie, Y. Gao, N.J. Ianno, L. Jiang, and Y.F. Lu:
Single-step formation of graphene on dielectric surfaces. Adv.
Mater. 25, 630 (2013).
41. J. Wintterlin and M-L. Bocquet: Graphene on metal surfaces.
Surf. Sci. 603, 1841 (2009).
42. C. Oshima and A. Nagashima: Ultra-thin epitaxial films of
graphite and hexagonal boron nitride on solid surfaces. J. Phys.:
Condens. Matter 9, 1 (1997).
43. A. Cabrero-Vilatela, R.S. Weatherup, P. Braeuninger-Weimer,
S. Caneva, and S. Hofmann: Towards a general growth model
for graphene CVD on transition metal catalysts. Nanoscale 8,
2149 (2016).
44. A.T.T. Koh, Y.M. Foong, and D.H.C. Chua: Comparison of the
mechanism of low defect few-layer graphene fabricated on
different metals by pulsed laser deposition. Diam. Relat. Mater.
25, 98 (2012).
45. J-i. Fujita, R. Ueki, Y. Miyazawa, and T. Ichihashi:
Graphitization at interface between amorphous carbon and liquid
gallium for fabricating large area graphene sheets. J. Vac. Sci.
Technol. B 27, 3063 (2009).
46. J.J. Schneider: Transforming amorphous into crystalline carbon:
Observing how graphene grows. ChemCatChem 3, 1119 (2011).
47. C. Mattevi, H. Kim, and M. Chhowalla: A review of chemical
vapour deposition of graphene on copper. J. Mater. Chem. 21,
3324 (2011).
48. H. Okamoto, M.E. Schlesinger, and E.M. Mueller (eds): ASM
Handbook, Alloy Phase Diagrams, Vol. 3 (ASM International,
Materials Park, OH, 2016); pp. 110–131.
49. G.A. López and E.J. Mittemeijer: The solubility of C in solid Cu.
Scr. Mater. 51, 1 (2004).
50. L. Baraton, Z.B. He, C.S. Lee, C.S. Cojocaru, M. Châtelet,
J-L. Maurice, Y.H. Lee, and D. Pribat: On the mechanisms of
precipitation of graphene on nickel thin films. Europhys. Lett. 96,
46003 (2011).
51. F.J. Derbyshire, A.E.B. Presland, and D.L. Trimm: Graphite
formation by the dissolution-precipitation of carbon in cobalt,
nickel and iron. Carbon 13, 111 (1975).
52. H. Ji, Y. Hao, Y. Ren, M. Charlton, W.H. Lee, Q. Wu, H. Li,
Y. Zhu, Y. Wu, R. Piner, and R.S. Ruoff: Graphene growth
Review
j
Journal
of
Materials
Research
j
Volume
35
j
Issue
1
j
Jan
14,
2020
j
www.mrs.org/jmr
Downloaded
from
University
of
Nebraska
Lincoln,
on
14
Jan
2020
at
13:14:10,
subject
to
the
Cambridge
Core
terms
of
use,
available
at
https://doi.org/10.1557/jmr.2019.377

using a solid carbon feedstock and hydrogen. ACS Nano 5, 7656
(2011).
53. R. Sinclair, T. Itoh, and R. Chin: In situ TEM studies of metal–
carbon reactions. Microsc. Microanal. 8, 288 (2002).
54. R. Kikowatz, K. Flad, and G. Hörz: Effects of carbon and sulfur
on the decomposition of hydrocarbons on nickel. J. Vac. Sci.
Technol. A 5, 1009 (1987).
55. W. Liu, H. Li, C. Xu, Y. Khatami, and K. Banerjee: Synthesis of
high-quality monolayer and bilayer graphene on copper using
chemical vapor deposition. Carbon 49, 4122 (2011).
56. X. Liu, L. Fu, N. Liu, T. Gao, Y. Zhang, L. Liao, and Z. Liu:
Segregation growth of graphene on Cu–Ni alloy for precise layer
control. J. Phys. Chem. C 115, 11976 (2011).
57. X. Chen, L. Zhang, and S. Chen: Large area CVD growth of
graphene. Synth. Met. 210, 95 (2015).
58. H. Sojoudi and S. Graham: Transfer-free selective area synthesis
of graphene using solid-state self-segregation of carbon in Cu/Ni
bilayers. ECS J. Solid State Sci. Technol. 2, M17 (2013).
59. K.L. Saenger, J.C. Tsang, A.A. Bol, J.O. Chu, A. Grill, and
C. Lavoie: In situ x-ray diffraction study of graphitic carbon
formed during heating and cooling of amorphous-C/Ni bilayers.
Appl. Phys. Lett. 96, 153105 (2010).
60. E. Sutter, P. Albrecht, and P. Sutter: Graphene growth on
polycrystalline Ru thin films. Appl. Phys. Lett. 95, 133109 (2009).
61. W. Knaepen, S. Gaudet, C. Detavernier, R.L. Van Meirhaeghe,
J.J. Sweet, and C. Lavoie: In situ x-ray diffraction study of metal
induced crystallization of amorphous germanium. J. Appl. Phys.
105, 083532 (2009).
62. K. Wang: Laser based fabrication of graphene. In Advances in
Graphene Science (M. Aliofkhazraci (ed) IntechOpen, London,
UK, 2013); ch. 4; pp. 77–95.
63. M.H. Ani, M.A. Kamarudin, A.H. Ramlan, E. Ismail, M.S. Sirat,
M.A. Mohamed, and M.A. Azam: A critical review on the
contributions of chemical and physical factors toward the nucleation
and growth of large-area graphene. J. Mater. Sci. 53, 7095 (2018).
64. A. Dahal and M. Batzill: Graphene–nickel interfaces: A review.
Nanoscale 6, 2548 (2014).
65. C. Gong, G. Lee, B. Shan, E.M. Vogel, R.M. Wallace, and
K. Cho: First-principles study of metal–graphene interfaces. J.
Appl. Phys. 108, 123711 (2010).
66. G.H. Han, F. Günes, J.J. Bae, E.S. Kim, S.J. Chae, H-J. Shin,
J-Y. Choi, D. Pribat, and Y.H. Lee: Influence of copper
morphology in forming nucleation seeds for graphene growth.
Nano Lett. 11, 4144 (2011).
67. S. Nie, J.M. Wofford, N.C. Bartelt, O.D. Dubon, and
K.F. McCarty: Origin of the mosaicity in graphene grown on
Cu(111). Phys. Rev. B 84, 155425 (2011).
68. H. Kim, C. Mattevi, M.R. Calvo, J.C. Oberg, L. Artiglia,
S. Agnoli, C.F. Hirjibehedin, M. Chhowalla, and E. Saiz:
Activation energy paths for graphene nucleation and growth on
Cu. ACS Nano 6, 3614 (2012).
69. C-M. Seah, S-P. Chai, and A.R. Mohamed: Mechanisms of
graphene growth by chemical vapour deposition on transition
metals. Carbon 70, 1 (2014).
70. M. Losurdo, M.M. Giangregorio, P. Capezzuto, and G. Bruno:
Graphene CVD growth on copper and nickel: Role of hydrogen
in kinetics and structure. Phys. Chem. Chem. Phys. 13, 20836
(2011).
71. Q. Yu, J. Lian, S. Siriponglert, H. Li, Y.P. Chen, and S-S. Pei:
Graphene segregated on Ni surfaces and transferred to insulators.
Appl. Phys. Lett. 93, 113103 (2008).
72. X. Li, W. Cai, J. An, S. Kim, J. Nah, D. Yang, R. Piner,
A. Velamakanni, I. Jung, E. Tutuc, S.K. Benerjee, L. Colombo,
and R.S. Ruoff: Large-area synthesis of high-quality and uniform
graphene films on copper foils. Science 324, 1312 (2009).
73. A.A. Woodworth and C.D. Stinespring: Surface chemistry of Ni
induced graphite formation on the 6H-SiC(0 0 0 1) surface and
its implications for graphene synthesis. Carbon 48, 1999 (2010).
74. O.S. Panwar, A.K. Kesarwani, S.R. Dhakate, and
B.S. Satyanarayana: Graphene synthesized using filtered
cathodic vacuum arc technique and its applications. Vacuum 153,
262 (2018).
75. N. Liu, L. Fu, B. Dai, K. Yan, X. Liu, R. Zhao, Y. Zhang, and
Z. Liu: Universal segregation growth approach to wafer-size
graphene from non-noble metals. Nano Lett. 11, 297 (2011).
76. Z-Y. Juang, C-Y. Wu, C-W. Lo, W-Y. Chen, C-F. Huang,
J-C. Hwang, F-R. Chen, K-C. Leou, and C-H. Tsai: Synthesis of
graphene on silicon carbide substrates at low temperature.
Carbon 47, 2026 (2009).
77. J. Hofrichter, B.N. Szafranek, M. Otto, T.J. Echtermeyer,
M. Baus, A. Majerus, V. Geringer, M. Ramsteiner, and
H. Kurz: Synthesis of graphene on silicon dioxide by a solid
carbon source. Nano Lett. 10, 36 (2010).
78. C. Li, D. Li, J. Yang, X. Zeng, and W. Yuan: Preparation of
single- and few-layer graphene sheets using Co deposition on SiC
substrate. J. Nanomater. 2011, 319624 (2011).
79. T. Yoneda, M. Shibuya, K. Mitsuhara, A. Visikovskiy,
Y. Hoshino, and Y. Kido: Graphene on SiC(0001) and SiCð000
1Þ
surfaces grown via Ni-silicidation reactions. Surf. Sci. 604, 1509
(2010).
80. S-M. Yoon, W.M. Choi, H. Baik, H-J. Shin, I. Song,
M-S. Kwon, J.J. Bae, H. Kim, Y.H. Lee, and J-Y. Choi: Synthesis
of multilayer graphene balls by carbon segregation from nickel
nanoparticles. ACS Nano 6, 6803 (2012).
81. J.H. Seo, H.W. Lee, J-K. Kim, D-G. Kim, J-W. Kang,
M-S. Kang, and C.S. Kim: Few layer graphene synthesized by
filtered vacuum arc system using solid carbon source. Curr. Appl.
Phys. 12, S131 (2012).
82. T. Tite, V. Barnier, C. Donnet, A-S. Loir, S. Reynaud,
J-Y. Michalon, F. Vocanson, and F. Garrelie: Surface enhanced
Raman spectroscopy platform based on graphene with one-year
stability. Thin Solid Films 604, 74 (2016).
Review
j
Journal
of
Materials
Research
j
Volume
35
j
Issue
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Jan
14,
2020
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83. A. Barreiro, F. Börrnert, S.M. Avdoshenko, B. Rellinghaus,
G. Cuniberti, M.H. Rümmeli, and L.M.K. Vandersypen:
Understanding the catalyst-free transformation of amorphous
carbon into graphene by current-induced annealing, Sci. Rep. 3,
1115 (2013).
84. Z.H. Ni, H.M. Wang, Y. Ma, J. Kasim, Y.H. Wu, and
Z.X. Shen: Tunable stress and controlled thickness modification
in graphene by annealing. ACS Nano 2, 1033 (2008).
85. P. Kumar: Laser flash synthesis of graphene and its inorganic
analogues: An innovative breakthrough with immense promise.
RSC Adv. 3, 11987 (2013).
86. Z. Yang and J. Hao: Progress in pulsed laser deposited two-
dimensional layered materials for device applications. J. Mater.
Chem. C 4, 8859 (2016).
87. Y. Bleu, F. Bourquard, T. Tite, A-S. Loir, C. Maddi, C. Donnet,
and F. Garrelie: Review of graphene growth from a solid carbon
source by pulsed laser deposition (PLD). Front. Chem. 6, 572 (2018).
88. A.M. Abd Elhamid, A.M. Aboulfotouh, M.A. Hafez, and
I.M. Azzouz: Room temperature graphene growth on complex
metal matrix by PLD. Diam. Relat. Mater. 80, 162 (2017).
89. V. Kaushik, H. Sharma, A.K. Shukla, and V.D. Vankar: Sharp
folded graphene ribbons formed by CO2 laser ablation for
electron field emission studies. Vacuum 110, 1 (2014).
90. K. Koshida, K. Gumi, Y. Ohno, K. Maehashi, K. Inoue, and
K. Matsumoto: Position-controlled direct graphene synthesis on
silicon oxide surfaces using laser irradiation. Appl. Phys. Exp. 6,
105101 (2013).
91. K. Wang, G. Tai, K.H. Wong, S.P. Lau, and W. Guo: Ni
induced few-layer graphene growth at low temperature by pulsed
laser deposition. AIP Adv. 1, 022141 (2011).
92. I. Kumar and A. Khare: Multi- and few-layer graphene on
insulating substrate via pulsed laser deposition technique. Appl.
Surf. Sci. 317, 1004 (2014).
93. M.G. Lemaitre, S. Tongay, X. Wang, D.K. Venkatachalam,
J. Fridmann, B.P. Gila, A.F. Hebard, F. Ren, R.G. Elliman, and
B.R. Appleton: Low-temperature, site selective graphitization of
SiC via ion implantation and pulsed laser annealing. Appl. Phys.
Lett. 100, 193105 (2012).
94. S.S. Kim, S. Hishita, T.S. Cho, and J.H. Je: Graphitization of
ultrathin amorphous carbon films on Si(001) by Ar1
ion
irradiation at ambient temperature. J. Appl. Phys. 88, 55 (2000).
95. S.S. Tinchev: Surface modification of diamond-like carbon films
to graphene under low energy ion beam irradiation. Appl. Surf.
Sci. 258, 2931 (2012).
96. F. Börrnert, S.M. Avdoshenko, A. Bachmatiuk, I. Ibrahim,
B. Büchner, G. Cuniberti, and M.H. Rümmeli: Amorphous
carbon under 80 kV electron irradiation: A means to make or
break graphene. Adv. Mater. 24, 5630 (2012).
97. A. Yajima, S. Abe, T. Fuse, Y. Mera, K. Maeda, and K. Suzuki:
Electron-irradiation-induced ordering in tetrahedral-amorphous
carbon films. Mol. Cryst. Liq. Cryst. 388, 147 (2002).
98. D. Ugarte: Curling and closure of graphitic networks under
electron-beam irradiation. Nature 359, 707 (1992).
99. G.C. Loh and D. Baillargeat: Graphitization of amorphous
carbon and its transformation pathways. J. Appl. Phys. 114,
033534 (2013).
100. A. Onodera, Y. Irie, K. Higashi, J. Umemura, and T. Takenaka:
Graphitization of amorphous carbon at high pressures to 15 GPa.
J. Appl. Phys. 69, 2611 (1991).
101. K.S. Subrahmanyam, L.S. Panchakarla, A. Govindaraj, and
C.N.R. Rao: Simple method of preparing graphene flakes by an
arc-discharge method. J. Phys. Chem. C 113, 4257 (2009).
102. Z-S. Wu, W. Ren, L. Gao, J. Zhao, Z. Chen, B. Liu, D. Tang,
B. Yu, C. Jiang, and H-M. Cheng: Synthesis of graphene sheets
with high electrical conductivity and good thermal stability by
hydrogen arc discharge exfoliation. ACS Nano 3, 411 (2009).
103. Y. Chen, H. Zhao, L. Sheng, L. Yu, K. An, J. Xu, Y. Ando, and
X. Zhao: Mass-production of highly-crystalline few-layer
graphene sheets by arc discharge in various H2–inert gas
mixtures. Chem. Phys. Lett. 538, 72 (2012).
104. Y. Miyamoto, H. Zhang, and D. Tománek: Photoexfoliation of
graphene from graphite: An ab initio study. Phys. Rev. Lett. 104,
208302 (2010).
105. M. Qian, Y.S. Zhou, Y. Gao, J.B. Park, T. Feng, S.M. Huang,
Z. Sun, L. Jiang, and Y.F. Lu: Formation of graphene sheets
through laser exfoliation of highly ordered pyrolytic graphite.
Appl. Phys. Lett. 98, 173108 (2011).
106. F. Bonaccorso, A. Lombardo, T. Hasan, Z. Sun, L. Colombo,
and A.C. Ferrari: Production and processing of graphene and 2d
crystals. Mater. Today 15, 564 (2012).
107. S.R. Sarath Kumar and H.N. Alshareef: Ultraviolet laser
deposition of graphene thin films without catalytic layers. Appl.
Phys. Lett. 102, 012110 (2013).
108. R.H. Benhagouga, S. Abdelli-Messaci, M. Abdesselam,
V. Blondeau-Patissier, R. Yahiaoui, M. Siad, and A. Rahal:
Temperature effect on hydrogenated amorphous carbon leading
to hydrogenated graphene by pulsed laser deposition. Appl. Surf.
Sci. 426, 874 (2017).
109. A.T.T. Koh, Y.M. Foong, and D.H.C. Chua: Cooling rate and
energy dependence of pulsed laser fabricated graphene on nickel
at reduced temperature. Appl. Phys. Lett. 97, 114102 (2010).
110. S.Z. Mortazavi, P. Parvin, and A. Reyhani: Fabrication of
graphene based on Q-switched Nd:YAG laser ablation of graphite
target in liquid nitrogen. Laser Phys. Lett. 9, 547 (2012).
111. B.C. Banerjee and P.L. Walker, Jr.: Interaction of evaporated
carbon films with nickel. J. Appl. Phys. 33, 229 (1962).
112. H. Lux, M. Edling, P. Siemroth, and S. Schrader: Fast and cost-
effective synthesis of high-quality graphene on copper foils using
high-current arc evaporation. Materials 11, 804 (2018).
113. D.T. Oldfield, D.G. McCulloch, C.P. Huynh, K. Sears, and
S.C. Hawkins: Multilayered graphene films prepared at moderate
Review
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temperatures using energetic physical vapour deposition. Carbon
94, 378 (2015).
114. J. Azpeitia, G. Otero-Irurueta, I. Palacio, J.I. Martinez, N. Ruiz
del Árbol, G. Santoro, A. Gutiérrez, L. Aballe, M. Foerster,
M. Kalbac, V. Vales, F.J. Mompeán, M. García-Hernández,
J.A. Martín-Gago, C. Munuera, and M.F. López: High-quality
PVD graphene growth by fullerene decomposition on Cu foils.
Carbon 119, 535 (2017).
115. G. Zhao, D. Shao, C. Chen, and X. Wang: Synthesis of few-
layered graphene by H2O2 plasma etching of graphite. Appl. Phys.
Lett. 98, 183114 (2011).
116. H. Tanaka, R. Arima, M. Fukumori, D. Tanaka, R. Negishi,
Y. Kobayashi, S. Kasai, T.K. Yamada, and T. Ogawa: Method
for controlling electrical properties of single-layer graphene
nanoribbons via adsorbed planar molecular nanoparticles. Sci.
Rep. 5, 12341 (2015).
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