Indonesian Journal of
Electrical
Engineer
ing and
Computer Science
V
o
l. 10
, No
. 3, Jun
e
20
18
, pp
. 89
7
~
90
4
ISSN: 2502-4752,
DOI: 10.
11591/ij
eecs.v10
.i3.pp897-904
8
97
Jo
urn
a
l
h
o
me
pa
ge
: http://iaescore.c
om/jo
urnals/index.php/ijeecs
Back-
t
o-
Back S
c
hottky Diode
f
rom Vacu
um Filtered and
Chemically Reduced Graphene Oxide
Siti Nadi
ah
Che Az
mi
1
, Sh
aharin
Fadz
li
Abd
Rahm
an
2
, Abdul
Man
a
f H
a
shim
3
1,2
Faculty
of Electrical
En
g
i
neer
ing, Universiti Te
knologi Malay
s
ia, Malay
s
ia
3
Malay
s
ia-Jap
an
Intern
ation
a
l
In
stitute of
Techno
log
y
, Univ
ers
iti
Teknologi
Mal
a
y
s
ia, Malay
s
i
a
Article Info
A
B
STRAC
T
Article histo
r
y:
Received
Ja
n 15, 2018
Rev
i
sed
Mar
12
, 20
18
Accepted
Mar 28, 2018
This paper prese
n
ts fabrica
tion o
f
re
duced gr
aphe
ne oxide (rGO)/
s
ilicon (Si)
back-to-b
ack Schottk
y
d
i
ode (B
BSD) through gr
aphene oxid
e
(GO) thin film
formation b
y
v
acuum filtration
and
chemical
reduction of
th
e film via
ascorbic acid
. In order to understand
and assess the viability
o
f
these two
processes, process condition
and
parameters were varied and
analy
z
ed. I
t
was
confirm
e
d th
at t
h
e GO film
thic
kness c
ould be
controlled b
y
ch
anging GO
dispersion volum
e and concent
r
ation
.
Filtration
of 200
m
l
of 0
.
4 ppm
GO
dispersion produced average f
i
lm thickness of
53 nm. As for the reduction
process, long duration was required to
produce h
i
gher reduction
degree. rGO
film that und
er
went two times
reduction
at
bef
o
re and
after
tra
n
s
f
er proces
s
with con
centr
at
ed as
corb
ic
ac
i
d
gave
the
low
e
s
t
s
h
ee
t res
i
s
t
a
n
ce of
3.58
M
Ω
/sq. In the
fi
nal p
a
rt of
the
p
a
per,
result
of
th
e BBSD devic
e
fabric
ation
and curren
t
-voltage ch
aracter
i
zation we
re show
n. The fo
rmed two rGO/Si
Schottk
y
jun
c
tio
ns in the BBSD gave b
a
rrier height of 0
.
63 and
0.7 eV. Th
e
presented
results confirmed th
e viabi
lity
of f
a
bricating rGO-b
a
sed dev
i
ce
using a simple method
and witho
u
t requ
irement o
f
sophis
ticated
equipment.
K
eyw
ords
:
Back-to-B
ack
S
c
hottk
y Diod
e
Vacuum
filtr
at
io
n
Copyright ©
201
8 Institut
e
o
f
Ad
vanced
Engin
eer
ing and S
c
i
e
nce.
All rights re
se
rve
d
.
Co
rresp
ond
i
ng
Autho
r
:
Sha
h
ari
n
Fa
dzl
i
Ab
d R
a
hm
an,
Facu
lty of Electri
cal Engineering,
Un
i
v
ersiti Tekn
o
l
o
g
i
Malaysia,
8
131
0 Joho
r B
a
h
r
u
,
Joho
r, M
a
laysia.
Em
a
il: sh
ah
ari
n
fad
z
li@u
t
m
.
my
1.
INTRODUCTION
Owi
ng t
o
gra
p
hene
’s
fasci
n
at
i
ng
pr
o
p
ert
i
e
s
and c
h
a
r
act
eri
s
t
i
c
s, i
t
has bee
n
re
gar
d
e
d
as
a pr
om
i
s
i
ng
m
a
t
e
ri
al
whi
c
h
coul
d re
v
o
l
u
t
i
oni
ze sem
i
con
duct
o
r a
n
d el
e
c
t
r
o
n
i
c
t
echn
o
l
ogy
. R
ece
nt
y
ears, e
f
f
o
rt
s
ha
v
e
bee
n
m
a
de t
o
i
n
co
r
p
o
r
at
e
gra
p
hen
e
i
n
t
o
exi
s
t
i
n
g
sem
i
conduct
o
r
devi
ces
i
n
o
r
der
t
o
e
n
han
c
e
de
vi
ce
per
f
o
r
m
a
nce
an
d
its fun
c
tio
n
a
lity [1-3
].
On
e
o
f
t
h
e si
m
p
lest g
r
ap
h
e
n
e
-b
ased
d
e
v
i
ces is Scho
ttky d
i
o
d
e
m
a
d
e
fro
m
gra
p
hene/
s
em
icon
d
u
ct
o
r
ju
n
c
t
i
on [4
, 5]
.
T
h
e devi
ce o
p
e
r
at
i
o
n
has
bee
n
al
rea
d
y
dem
onst
r
at
ed o
n
v
a
ri
o
u
s
semico
n
d
u
c
tors su
ch
as silico
n
(Si),
g
a
llium arsen
i
d
e
(GaAs), silico
n
carb
i
d
e
(SiC), an
d
g
a
lliu
m
n
itrid
e
(Ga
N
) [6-8]. E
l
ectrical characteristics
of t
h
e grap
he
ne/
s
e
m
i
c
ond
uct
o
r j
unct
i
o
n i
s
kn
o
w
n t
o
be s
u
sce
p
t
i
b
l
e
t
o
cert
a
i
n
m
o
l
ecul
e
s, t
hus m
a
ke i
t
favou
rabl
e t
o
be ex
pl
oi
t
e
d
i
n
desi
g
n
i
n
g and
fab
r
i
cat
i
n
g
el
ect
roni
c che
m
i
c
al
sens
or [
9
-
1
1]
.
Whe
n
t
w
o Sc
hot
t
k
y
el
ect
ro
des a
r
e
de
po
s
i
t
e
d o
n
t
o
a se
m
i
cond
uct
o
r s
ubst
r
at
e, a
si
m
p
l
e
devi
ce
st
ruct
u
r
e cal
l
e
d bac
k
-t
o
-
bac
k
Sc
hot
t
k
y
di
ode
(B
B
S
D)
coul
d
be f
o
rm
ed. T
h
e B
B
S
D ha
s si
m
p
l
e
devi
ce
st
ruct
u
r
e com
p
ared t
o
a com
m
on si
ngl
e Schot
t
k
y
di
ode a
nd i
t
has bee
n
i
nvest
i
g
at
e
d
f
o
r vari
ou
s ap
pl
i
cat
i
ons
suc
h
as ph
ot
o
d
et
ect
or a
nd s
e
ns
ors [
1
2, 1
3
]
. In spi
t
e
of t
h
e adva
nt
age
s
of t
h
e B
B
S
D
,
rep
o
rt
e
d
wo
r
k
o
n
gra
p
hene B
B
S
D i
s
rel
a
t
i
v
el
y
l
i
m
i
t
e
d. Thi
s
wo
rk
f
o
cu
ses
on
fa
bri
cat
i
o
n
of
gra
p
he
ne B
B
SD st
r
u
ct
u
r
e
usi
n
g
si
m
p
le an
d
low co
st fab
r
icat
io
n
techn
i
qu
e. A h
i
gh
-
q
u
a
lity g
r
aph
e
ne g
r
o
w
n
b
y
ch
em
i
cal v
a
p
our d
e
po
sitio
n
(C
V
D
) t
e
c
h
ni
q
u
e m
a
y
not
be
sui
t
a
bl
e f
o
r m
a
ss p
r
o
d
u
ct
i
o
n
of
a l
o
w c
o
st
B
B
S
D
devi
ce.
An
al
t
e
rnat
i
v
e
of t
h
e
Evaluation Warning : The document was created with Spire.PDF for Python.
I
S
SN
:
2
502
-47
52
I
ndo
n
e
sian
J Elec Eng
& Com
p
Sci, V
o
l. 10
,
No
.
3
,
Jun
e
2
018
:
89
7 – 90
4
89
8
C
VD
gra
p
hene
i
s
reduc
ed
gra
phe
ne
oxi
de (
r
G
O
)
. T
h
e r
G
O
i
s
a grap
he
ne
deri
vat
i
v
e,
whi
c
h can
be ch
e
m
i
cal
l
y
fun
c
tion
a
lized
to
m
o
d
i
fy its p
r
op
erties an
d
t
o
en
ab
le selectiv
e sen
s
i
n
g
operatio
n
[14
]
. In
th
is work, an
rGO
fi
lm
was obt
ai
ned
by
m
eans of vac
u
um
fi
lt
rat
i
on of
gra
p
h
e
ne o
x
i
d
e (
G
O
)
di
spe
r
si
o
n
an
d chem
i
cal reduct
i
o
n
p
r
o
cess.
Un
d
e
rstan
d
i
n
g
t
h
ese two
p
r
o
cesses is
sig
n
i
fican
t
in
ord
e
r to
en
su
re the feasib
il
ity an
d
reliab
ility o
f
the ove
r
all fa
brication process
of the
BBSD
device.
In
v
acuu
m
filt
ratio
n
p
r
o
cess, v
o
l
u
m
e o
f
GO d
i
sp
ersi
o
n
was v
a
ried
to
ev
alu
a
te th
e po
ssib
ility o
f
co
n
t
ro
lling
GO th
in film
t
h
ickn
ess.
On
e
m
u
st b
e
ab
le to
con
t
ro
l thin
film
th
ick
n
e
ss wh
en fab
r
icatin
g
sem
i
cond
uct
o
r
devi
ce
. As
f
o
r chem
i
cal
reduct
i
o
n
p
r
oc
e
s
s
,
ascorbic aci
d (L-AA)
was
use
d
as a re
duction
ag
en
t.
L-AA is a n
a
tural and
safe redu
ctio
n
ag
en
t th
at is
as
efficient as
widely use
d
re
duction age
n
t s
u
c
h
a
s
hy
d
r
azi
ne [
1
5-
17]
. E
ffect
of r
e
duct
i
o
n t
i
m
e
and L
-
AA c
o
n
cent
r
at
i
o
n was
i
nvest
i
g
at
e
d
. B
e
si
des, t
h
i
s
wo
rk al
s
o
assessed
whet
her t
h
e
pr
oces
s seque
nce ha
s
si
gni
fi
cant
i
n
fluence on the
electrical
characteristics of the rGO
fil
m
. In
t
h
e
final sectio
n
o
f
this p
a
per, the el
ectrical charact
eristic of th
e
fa
bricated BBSD is prese
n
ted.
From
the current
-
vol
t
age (
I
-
V)
ch
aracteristic, th
e j
u
n
c
tio
n
p
r
operties, n
a
m
e
ly
b
a
rrier h
e
igh
t
, id
eality facto
r
and
series resistanc
e
were e
x
tract
ed. T
h
e ext
r
action
of th
e
Scho
ttk
y ju
n
c
tion
p
r
op
erties is sig
n
i
fican
t in
ord
e
r t
o
allo
w an
alysis o
f
th
e BBSD
op
eration
.
2.
R
E
SEARC
H M
ETHOD
A GO th
in
film was fo
rm
ed
b
y
sep
a
rating GO fl
a
k
e f
r
o
m
di
spersi
o
n
sol
u
t
i
o
n t
h
ro
u
gh
vac
uum
filtratio
n
.
GO aq
u
e
ou
s
d
i
sp
ersion
with
sp
ecific v
o
l
u
m
e
an
d
con
cen
t
r
atio
n
was filtered
th
roug
h
a
mix
e
d
cellu
lo
se ester me
m
b
ran
e
(M
CE) with
av
erag
e po
re size o
f
20
n
m
. Prior to
th
e filtr
atio
n, th
e GO d
i
sp
ersi
o
n
was d
i
l
u
ted
to
certain
con
c
en
tratio
n
s
and
was u
ltraso
n
i
cated
fo
r
1
h
o
u
r
. Th
is is to
allo
w
th
e GO flak
es
to
be
di
spe
r
se
d e
v
en
l
y
i
n
si
de t
h
e
a
que
o
u
s s
o
l
u
t
i
o
n.
G
O
fi
l
m
s were
pre
p
are
d
fr
om
di
spersi
on
wi
t
h
vol
um
e of 5
0
,
10
0,
15
0 an
d
20
0 m
l
. The
conce
n
t
r
at
i
o
n
of t
h
e di
s
p
er
si
on
was fi
xe
d
at
0.4 p
p
m
.
The sel
ect
ed pr
ocess
param
e
t
e
rs we
re ad
o
p
t
e
d f
r
o
m
repo
rt
ed
wo
rk
do
ne
by
G
o
ki
Eda
et al
. [
1
8]
. O
u
r
prel
i
m
inary
e
xpe
ri
m
e
nt
has
sho
w
n t
h
at
t
h
e
GO
fi
l
m
t
h
i
c
kness c
o
ul
d
not
be
preci
sel
y
de
t
e
rm
i
n
ed w
h
e
n
t
h
e G
O
i
s
o
n
t
h
e r
o
ug
h s
u
rfa
ce of
MCE filter. Th
e filtered
film n
eed
ed
to
b
e
tran
sfer
red o
n
t
o
g
l
ass su
b
s
t
r
ate b
e
fo
re it
is read
y
to
be
characte
r
ized
by Atom
ic Force Microsc
ope (AFM
).
From th
e AFM imag
es, film
th
ick
n
e
ss and
rou
ghn
ess
was a
n
alyzed.
Next
,
f
o
r
i
n
ves
t
i
g
at
i
on
of
re
d
u
ct
i
o
n
pr
ocess
vi
a L
-
A
A
s
o
l
u
t
i
on,
t
w
o L
-
A
A
c
onc
ent
r
at
i
o
ns
(i
.e.
0
.
4
6
m
g
/
m
l
an
d
13
.6
m
g
/
m
l) were co
n
s
idered
. Th
e con
cen
t
r
atio
n
v
a
lu
es were selected
after rev
i
ewing
mu
ltip
le
rep
o
rt
e
d
w
o
r
k
s
.
R
e
duct
i
o
n p
r
ocess wa
s d
o
n
e
by
im
m
e
rsi
ng t
h
e G
O
fi
l
m
i
n
t
o
L-
AA s
o
l
u
t
i
on
heat
ed at
80 °C
fo
r vari
ou
s du
r
a
t
i
ons ra
ngi
ng
fr
om
5
t
o
7
2
0
m
i
nut
es.
T
h
e p
u
r
p
ose of
t
h
i
s
obs
er
vat
i
o
n
wa
s
t
o
i
d
e
n
t
i
f
y
t
h
e
t
i
m
e
whe
n
t
h
e red
u
c
t
i
on pr
ocess
co
m
p
l
e
t
e
d.
It
i
s
wo
rt
h t
o
hi
g
h
l
i
g
ht
t
h
at
m
o
st
of t
h
e
rep
o
rt
e
d
w
o
r
k
s o
n
re
duct
i
o
n
p
r
oces
s
were
usi
n
g
G
O
dispe
r
sio
n
rath
er tha
n
G
O
fil
m
[15,
16]. In
case of the
GO thi
n
film
red
u
c
tion
,
on
ly th
e
GO on
film surface
are ex
po
sed
t
o
L-AA so
lu
tion
.
Sub
s
equ
e
n
t
l
y
, th
e
GO
o
n
t
h
e su
rface will b
e
h
i
g
h
l
y
redu
ced co
m
p
ared to
t
h
at
at the center of the film
.
In the actual fa
bri
cation process
flow of
our B
B
SD de
vice, t
h
e chem
ical reduction
pr
ocess can
be
do
ne bef
o
re o
r
/
a
n
d
aft
e
r t
r
an
sfer o
f
G
O
fi
l
m
ont
o Si
subs
t
r
at
e. Tabl
e 1 l
i
s
t
s
up fo
ur
po
ssi
bl
e
p
r
o
cess co
nd
itio
n
s
con
s
id
ered in
th
is wo
rk
.
Th
e
d
i
ffere
n
c
e b
e
tween
th
ese fou
r
con
d
itions after redu
ction
and
trans
f
er was
depicted i
n
t
h
e
table. For RGO1 a
n
d
RGO2, only
one
s
u
rface was
e
x
pos
e
d t
o
L
-
AA solution.
Fo
r
R
G
O3
and
RG
O4
,
r
e
ductio
n
w
a
s
d
one tw
ice w
h
ich ar
e
b
e
fo
r
e
and
a
f
te
r
th
e
tr
an
s
f
er
.
In
s
u
ch
ma
n
n
e
r,
bot
h thin film
surfaces are e
x
pos
ed
to the L-AA. The re
duc
e
d GO was ch
a
r
acterized by R
a
m
a
n Spectros
c
opy
w
ith
laser w
a
velen
g
t
h of
51
4.5
n
m
to
an
alyze th
e ch
em
i
cal st
ruct
ural
c
h
a
nge
u
p
o
n
t
h
e
r
e
duct
i
o
n
p
r
oce
ss. T
o
evaluate the el
ectrical prope
rties of
t
h
e
rG
O, t
h
e
r
GO
we
re t
r
an
sfe
rre
d
ont
o t
h
e
r
m
a
ll
y oxi
di
zed Si
s
u
bst
r
at
e.
Sheet resistanc
e
of the rGO
film
was
m
eas
ure
d
usi
n
g fo
u
r
-
poi
nt
pr
o
b
e
m
easur
em
ent with
source-measure
u
n
it
(Keith
ley
m
o
d
e
l 2
4
0
0
).
Based
o
n
th
e
ob
tain
ed Ram
a
n
sp
ectru
m
an
d
sh
eet resistan
ce, th
e co
m
p
atib
ility o
f
p
r
o
cess cond
itio
n in
Tab
l
e
1
i
s
d
i
scu
ssed
.
Evaluation Warning : The document was created with Spire.PDF for Python.
In
d
onesi
a
n
J
E
l
ec En
g &
C
o
m
p
Sci
ISS
N
:
2
5
0
2
-
47
52
Ba
ck-t
o
-Ba
c
k
S
c
ho
ttky Di
od
e fro
m
Va
cuum
Filte
red
and
C
h
emica
lly… (S
iti Na
d
i
ah
C
h
e
Azmi)
89
9
Tabl
e
1.
Fo
ur
r
e
duct
i
o
n c
o
n
d
i
t
i
ons
use
d
i
n
t
h
i
s
wo
r
k
Condition label
Description
GO fil
m
after reduction and transfer
RGO1
Bef
o
re transf
er (0.
46
m
g
/
m
l
L-A
A
)
RGO2
Af
ter
transf
er (0.46 m
g
/
m
l L-
AA)
RGO3
Bef
o
re and af
ter tr
ansf
er (0.46
m
g
/
m
l
L-A
A
)
RGO4
Befor
e
and after
transfer
(
13.
6
m
g
/m
l L
-
AA)
Based on the result from
the
above
ex
peri
m
e
nt
s, t
h
e fab
r
i
c
at
i
on pr
ocess f
l
ow an
d p
r
oce
ss con
d
i
t
i
o
n
w
e
r
e
d
eci
d
e
d. Figu
r
e
1 sh
ow
s t
h
e layou
t
and
cr
oss-
sectio
n
o
f
th
e f
a
b
r
icated BBSD
an
d th
e f
a
br
icatio
n
pr
ocess fl
ow
.
For t
h
e act
ual
B
B
S
D de
vi
ce,
a GO
di
spe
r
si
on
wi
t
h
co
nce
n
t
r
at
i
o
n an
d v
o
l
u
m
e
at
0.4 p
p
m
and
2
0
0
m
l
, resp
ect
iv
ely were
u
s
ed
in
v
acuu
m
fil
t
ratio
n
p
r
o
cess. Th
e form
ed
GO
film
o
n
filter p
a
p
e
r
was cu
t in
to
0.
8 m
m
× 0.8
m
m
and t
h
en
was p
a
t
t
e
rne
d
i
n
t
o
a de
si
re
d
sha
p
e by
del
a
m
i
nat
i
ng u
n
w
a
nt
ed a
r
ea usi
n
g st
i
c
ky
pape
r.
The
pat
t
erne
d
GO
fi
l
m
was t
r
a
n
s
f
er
re
d
ont
o p
r
e-
cl
eaned
n
-
t
y
pe Si
s
ubst
r
at
e com
m
o
n
m
e
t
hod
use
d
by
ot
he
r resea
r
che
r
s. R
e
d
u
ct
i
o
n pr
ocess
was pe
rf
orm
e
d aft
e
r t
h
e t
r
ans
f
e
r
usi
ng
0.
46 m
g
/m
l L-A
A
sol
u
t
i
o
n at
8
0
°C fo
r 720
m
i
n
u
t
es. Th
e
d
e
v
i
ce fab
r
ication
was co
m
p
let
e
d
b
y
d
e
po
sitio
n of
go
ld
t
h
in
fil
m
o
n
t
o rGO v
i
a
p
h
o
t
o
litho
g
raph
y and
ion
co
ater. Th
e
pu
rpose o
f
go
ld
th
i
n
fil
m
d
e
p
o
s
ition
is to
m
i
n
i
mi
ze co
n
t
act resi
stan
ce
during probi
ng for electrica
l
m
easurem
ent. The elect
ric
a
l characteriza
tion of the fa
bricated BBSD was
per
f
o
r
m
e
d usi
ng s
o
urce
-m
easure
u
n
i
t
.
The
vol
t
a
ge
was
appl
i
e
d at
i
n
n
e
r r
GO el
ect
r
ode
, w
h
i
l
e
t
h
e
out
er
electrode
was
s
e
t as ground.
Fi
gu
re 1.
(a
)
St
ruct
ure o
f
t
h
e
B
B
S
D
a
n
d
(
b
)
Devi
ce fa
bri
cat
i
on p
r
oces
s
fl
o
w
3.
R
E
SU
LTS AN
D ANA
LY
SIS
3.1.
Vacuum filtered
GO film
Fi
gu
re 2 a
n
d 3
sho
w
s
AFM
i
m
ages and
hei
ght
pr
ofi
l
e
s f
o
r
GO
fi
lm
on gl
ass su
bst
r
at
es,
respect
i
v
el
y
.
From
the line
pr
ofile, t
h
e thi
c
kne
ss a
n
d
r
o
o
t
-m
ean-squa
re
(RM
S
)
ro
u
g
h
n
e
ss f
o
r e
ach
sa
m
p
le were dete
rm
ined
and plotte
d
in Figure 5.
T
h
e GO film
made
from
50
m
l
G
O
s
o
lution see
m
s
to have
gra
i
ny and
rough
surface
an
d
po
or
un
ifor
m
i
ty. I
t
s su
r
f
a
ce r
o
u
ghn
ess
w
a
s clear
ly h
i
ghe
r tha
n
ot
he
r sam
p
les. W
e
spec
ulate that in case
of
50 m
l
, the
num
ber of GO flakes was
not enough to
cove
r all the filter
m
e
m
b
rane surface. Above the
vol
um
e of 100
m
l
, t
h
e GO average t
h
i
c
knes
s
i
n
creased i
n
pr
o
p
o
r
t
i
onal
t
o
GO sol
u
t
i
on
v
o
l
u
m
e
. The
m
i
ni
m
u
m
fi
lm
t
h
i
c
kness
whi
c
h c
oul
d
b
e
o
b
t
a
i
n
e
d
usi
n
g
o
u
r
set
u
p
i
s
ar
ou
n
d
20
nm
. O
n
t
h
e
ot
he
r
han
d
,
n
o
si
g
n
i
f
i
cant
correlation bet
w
een dispersion
vol
um
e
and surface roughne
ss.
The roughness of
the formed film
is around
3
to
7
n
m
.
No
te th
at
th
e
effect o
f
tran
sfer p
r
ocess
to
th
e qu
ality o
f
th
e GO
fil
m
n
eed
s to
b
e
con
s
id
ered
wh
en
analyzing the
AFM im
ages. The observ
ed
crack
s, ripp
les an
d
fo
ld
s in
th
e AFM im
ag
es
m
i
ght be cause
d by
the
tra
n
sfe
r
process.
Au
Au
Si
Si
8m
m
x
8
mm
7
mm
x
7
mm
Si
rGO
rGO
rGO
Au
Au
Au
2.
5
mm
1m
m
2
mm
V
a
c
uum
f
ilt
r
a
t
i
o
n
Tr
a
n
s
f
e
r
pr
oc
e
s
s
R
e
duc
t
i
on
vi
a
as
c
o
r
b
i
c
ac
i
d
P
a
tte
r
n
i
n
g
RG
O
el
ec
t
r
o
d
e
Go
l
d
de
pos
i
t
i
on
(a)
(b)
rGO
Hi
g
hl
y
reduced
Substr
ate
rGO
Hi
g
hl
y
reduced
Substr
ate
Highly
r
e
duced
rGO
Substr
ate
Highly
r
e
duced
rGO
Substr
ate
Evaluation Warning : The document was created with Spire.PDF for Python.
I
S
SN
:
2
502
-47
52
I
ndo
n
e
sian
J Elec Eng
& Com
p
Sci, V
o
l. 10
,
No
.
3
,
Jun
e
2
018
:
89
7 – 90
4
90
0
Figu
re
2.
A
F
M
im
ages f
o
r
G
O
film
from
diffe
rent s
o
lu
ti
on
v
o
lum
e
((a)
5
0
, (
b
) 1
0
0
,
(c) 15
0
a
n
d (d
) 20
0
m
l
)
Fi
gu
re
3.
Hei
g
ht
p
r
ofi
l
e
s al
o
n
g
t
h
e
re
d l
i
n
e
i
n
t
h
e
A
F
M
i
m
ages
((e
)
50
,
(f
)
10
0,
(
g
)
1
5
0
a
n
d
(h
)
20
0 m
l
)
Fi
gu
re
4.
(a
)
A
v
era
g
e t
h
i
c
k
n
e
ss an
d
(b
)
r
o
u
g
hne
ss as
a f
u
nc
t
i
on
of
di
s
p
ersi
on
v
o
l
u
m
e
3.
2.
Re
duced
GO fi
l
m
In
o
r
d
e
r to
d
e
t
e
rm
in
e th
e ele
c
tron
ic an
d
st
ru
ctur
al propert
i
es changes in
GO a
nd
rGO film
, Ra
man
sp
ectro
sco
p
y
was carried
ou
t
to
in
terpret th
e ch
an
g
e
in
t
h
e
obt
ai
ne
d
spect
r
a
. Fi
g
u
re
5
sh
o
w
s R
a
m
a
n spe
c
t
r
a o
f
GO a
nd
rG
O.
Tw
o pr
om
i
n
en
t
peaks ap
pea
r
at
arou
n
d
1
3
4
7
and a
nd
15
9
7
cm
-1
, whi
c
h ar
e l
a
bel
l
e
d as D
and
G
peaks, res
p
ectively [19]. A s
o
calle
d 2D
band appeare
d
at
2688 cm
-1
. D
o
v
e
r G i
n
ten
s
ity ratio
(I
D
/I
G
) can
be
0
10
20
30
40
50
60
0
1
00
2
0
0
3
00
Thickness
(nm)
Dispersion
volume
(ml
)
0
5
10
15
20
25
30
0
1
00
2
0
0
3
00
RMS
ro
ughness
(nm)
Dispersion
volume
(ml
)
Scan Distance
(
a
)
(
b
)
(
c
)
(
d
)
(a
)
(b)
(c)
(d)
Evaluation Warning : The document was created with Spire.PDF for Python.
In
d
onesi
a
n
J
E
l
ec En
g &
C
o
m
p
Sci
ISS
N
:
2
5
0
2
-
47
52
Ba
ck-t
o
-Ba
c
k
S
c
ho
ttky Di
od
e fro
m
Va
cuum
Filte
red
and
C
h
emica
lly… (S
iti Na
d
i
ah
C
h
e
Azmi)
90
1
use
d
t
o
asses
s
t
h
e re
duct
i
o
n
d
e
gree
of
G
O
.
The
hi
g
h
er i
n
t
e
nsi
t
y
rat
i
o
i
n
d
i
cat
e hi
ghe
r re
duct
i
o
n
deg
r
ee
whi
c
h
is ge
nerally attributed t
o
a
de
crease
of the a
v
era
g
e si
ze of
th
e sp
2 do
m
a
i
n
s af
ter
t
h
e
r
e
du
ctio
n [17
]
. Based
on
Fi
gu
re 5,
I
D
/I
G
in
creased
fro
m
0
.
99
to 1.15
after th
e
redu
ction
.
Fi
gu
re
5.
R
a
m
a
n s
p
ect
ra
o
f
G
O
a
n
d
r
G
O
Fi
gu
re
6 s
u
m
m
a
ri
zes t
h
e
cha
n
ge
of
I
D
/I
G
ov
er redu
ction
time fo
r
d
i
ffer
en
t
redu
ction
co
nditio
n
.
Th
ere
was no
si
g
n
i
fi
can
t d
i
fferen
ce b
e
tween
all the redu
ctio
n
con
d
ition
s
. In
g
e
n
e
ral, h
i
gh
er red
u
c
tion
d
e
gree
was
ach
iev
e
d
at lon
g
e
r redu
ction ti
m
e
. No
clear sign
o
f
com
p
le
tio
n
of the redu
ction
p
r
o
cess ev
en
aft
e
r 720
minutes. This
result indicates
that co
m
p
ared
to
GO d
i
sp
ersi
o
n
redu
ction
,
GO t
h
in
film
red
u
c
tion
is a pro
cess
wi
t
h
m
u
ch sl
o
w
er
rat
e
. A
f
t
e
r 7
20 m
i
nut
es
red
u
ct
i
o
n, R
G
O
2
gave t
h
e
hi
g
h
est
I
D
/I
G
val
u
e. As depi
ct
ed
i
n
Table
1, the
c
h
aracterize
d
s
u
rface for sa
m
p
le RGO2
(i
.e. top s
u
rface
) is the
surfac
e
which
was
directly
exp
o
se
d t
o
L
-
AA
. Thi
s
e
xpl
ai
ns t
h
e di
ffe
r
e
nce bet
w
een
R
G
O
1
an
d R
G
O
2
. R
G
O
3
gave t
h
e l
o
we
st
I
D
/I
G
v
a
lu
e. In
case
o
f
do
ub
le-si
d
ed
redu
ctio
n, the redu
ctio
n
time is calcu
lated
as th
e to
tal
o
f
red
u
c
tion
tim
e
at b
o
t
h
si
des.
Fo
r
7
2
0
m
i
nut
es red
u
c
t
i
on,
re
duct
i
o
n
t
i
m
e for
o
n
e
si
de
was
36
0 m
i
nut
e.
We
spec
ul
at
e t
h
a
t
t
h
e
redu
ction
ti
m
e
was no
t lo
ng
en
oug
h
t
o
p
r
od
u
c
ed
h
i
gh
redu
ctio
n
d
e
g
r
ee.
Th
is resu
lted
in
th
e low I
D
/I
G
val
u
e.
R
G
O
4
gave
t
h
e sec
o
n
d
hi
g
h
est
re
d
u
ct
i
o
n
de
gree.
B
a
se
d
on t
h
e
obt
ai
ned
res
u
l
t
,
re
d
u
ct
i
o
n
aft
e
r
t
r
ansfe
r
pr
ocess
m
a
y
prod
uce bet
t
e
r re
duct
i
o
n de
gree
.
Fi
gu
re 6.
I
D
/I
G
as fu
n
c
tion
of red
u
c
tion
tim
e fo
r d
i
fferen
t con
d
ition
s
The re
duction
degree wa
s also eval
uated from
the
m
easure
m
ent of thin
film
sheet resistance. Film
wi
t
h
hi
g
h
re
d
u
c
t
i
on de
gree s
h
oul
d ha
ve l
o
w sheet
resi
st
anc
e
. Tabl
e 2 s
h
o
w
s t
h
e o
b
t
a
i
n
e
d
sheet
resi
st
a
n
ce f
o
r
sam
p
les after
d
i
fferen
t
redu
ctio
n
cond
itio
ns. Th
e re
du
ctio
n
tim
e was fix
e
d
at 72
0
m
i
n
u
t
es. Th
e obtain
e
d
result showed alm
o
st good
agreem
en
t with
th
e Ram
a
n
sp
ectro
sco
p
y
resu
lt. RGO4
h
a
s th
e lowest
sh
eet
resistance
of 3.58 M
Ω
/sq
.
Th
i
s
v
a
lu
e is in
t
h
e co
m
p
arab
le
or
der
wi
t
h
fi
n
d
i
ng rep
o
r
t
e
d b
y
G.
E
d
a
et al.
[1
8]
.
RGO2
con
d
itio
n g
a
v
e
second
lowest sh
eet
resistan
ce. The v
a
lu
e was
2
.
3
tim
es h
i
g
h
e
r th
an th
at
for
RGO4
.
Alth
oug
h th
e
RGO4
g
a
v
e
the lo
west
sheet
resistance
,
we
ha
ve c
h
osen the R
G
O2
proc
ess condition
for the
act
ual
fabri
cat
i
on
of t
h
e B
B
S
D. It
was f
o
un
d t
h
at
, chem
i
c
al
reduct
i
o
n be
fo
re t
r
ans
f
er
w
a
s pr
one t
o
G
O
fi
lm
d
e
lamin
a
tio
n
fro
m
th
e filter. Th
is m
a
y p
r
od
uce vo
id
and
crack
at th
e resu
lt
ed
rGO
fil
m
.
1000
2000
3000
4000
5000
6000
R
a
m
an s
h
i
ft (
cm-
1
)
Intens
ity
(
a
.u.)
GO
RG
O
D
G
2D
Evaluation Warning : The document was created with Spire.PDF for Python.
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52
I
ndo
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e
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J Elec Eng
& Com
p
Sci, V
o
l. 10
,
No
.
3
,
Jun
e
2
018
:
89
7 – 90
4
90
2
Tabl
e
2.
Sheet
resi
st
ance
of
r
G
O
fi
l
m
obt
ai
n
e
d
fr
om
di
ffere
nt
re
d
u
ct
i
o
n
co
ndi
t
i
o
n
Sa
m
p
le
Sheet resistance
(
M
Ω
/sq)
RGO1 15.
59
RGO2 8.
23
RGO3 13.
23
RGO4 3.
58
3.
2.
F
a
bri
c
a
t
e
d
B
B
S
D
de
vi
ce
Figure
7(a)
shows
the
im
age of tr
an
sferred
rGO
on
Si
substrate.
Alm
o
st all th
e p
a
ttern
ed
rGO
fil
m
was tran
sferred
on
to
th
e su
b
s
trate. Fig
u
re 7(b
)
sh
ow
s th
e co
m
p
leted
BBS
D d
e
v
i
ce after g
o
l
d
film d
e
p
o
sitio
n.
The m
easured
I
-
V
ch
aracteristics is sh
o
w
n
in
Figu
re
8. Th
e ob
tain
ed
curv
e sh
ows si
m
i
larity w
ith
th
e
ch
aracteristics o
f
a si
ng
le Scho
ttk
y d
i
o
d
e
. At
1
0
V, th
e
r
ectification
ratio (i
.e. current rati
o at forward
over at
reve
rse bi
as
) w
a
s 12
.1
6. T
h
e
r
e
l
a
t
i
v
el
y
hi
gh r
ect
i
f
i
cat
i
on rat
i
o
co
ul
d
be ex
p
l
ai
ned by
t
h
e
n
o
n
-
i
d
e
n
t
i
cal
area o
f
t
h
e t
w
o Sc
hot
t
k
y
j
u
nct
i
ons
i
n
t
h
e B
B
S
D
.
N
o
t
e
t
h
at
i
n
c
a
s
e
of
o
u
r
de
vi
c
e
an
d m
easure
m
ent
con
f
i
g
ur
at
i
on, at
p
o
s
itiv
e
b
i
as, t
h
e BBSD curren
t is d
e
term
in
ed
b
y
th
e
rev
e
rsed
b
i
ased
o
u
t
er Sch
o
ttk
y electrod
e.
On
t
h
e
o
t
h
e
r
h
a
nd
, wh
en
n
e
g
a
tiv
e
b
i
as is ap
p
lied, t
h
e inner circle
Scho
ttk
y electrod
e
will li
mit th
e cu
rren
t
v
a
lu
e. Si
nce the
o
u
t
er electrod
e
h
a
s larg
er area th
an
inn
e
r ci
rcle electro
d
e
, t
h
e cu
rren
t at positiv
e b
i
as b
e
ca
m
e
h
i
g
h
e
r th
an
th
at
i
n
ne
gat
i
v
e
bi
a
s
.
Fi
gu
re
7.
C
a
m
e
ra i
m
ages of
t
h
e
(a)
r
G
O
fi
l
m
on Si
an
d
(
b
) c
o
m
p
l
e
t
e
d B
B
S
D
devi
ce
Figure
8. I-V c
h
aracteristic
s
of the
fa
bricated BBSD
Scho
ttk
y p
a
rameters su
ch
as b
a
rrier
h
e
igh
t
, id
eality
facto
r
o
f
t
h
e two
j
u
n
c
tio
ns in
the
BBSD were
extracted
by adopting proce
d
ur
e pr
opo
sed b
y
S. Av
er
ine
et al
. Prior
to the extracti
o
n, effe
ct of
series
resistance was
excluded from
measurem
e
n
t resu
lt. Series resistan
ce is a to
tal resist
an
ce orig
in
ated
fro
m
gol
d/
r
GO c
o
nt
act
resi
st
ance,
rG
O resi
st
a
n
ce
and
Si
su
bs
tra
t
e resistance. T
h
e series
resistance wa
s calculated
fr
om
t
h
e sl
ope
of
I
-
V
lin
ear
reg
i
o
n
at h
i
gh p
o
s
itiv
e b
i
as
[20
]
. Th
e series resistan
ce was 84
3
Ω
. T
a
ble 3
su
mm
arizes th
e Scho
ttk
y p
a
ra
m
e
ters o
f
th
e
Scho
ttk
jun
c
tion in the
de
vice. The estim
ate
d
ba
rrie
r
hei
g
hts are
hi
g
h
er t
h
a
n
re
po
rt
ed
val
u
e
b
y
M
.
Zh
u
et al.
[21
]
.
It is d
i
fficu
lt to m
a
k
e
fair co
m
p
ariso
n
with th
e
rep
o
rted
wo
rk
as
t
h
e rG
O wo
rk
f
u
nctio
n
is
likely
diffe
rs with ou
r de
v
i
ce.
Tabl
e
3. T
h
e
e
x
t
r
act
ed
Sc
hot
t
k
y
pa
ram
e
t
e
rs
Schottky
par
a
m
e
ter
s
I
nner
electr
ode
junction
Outer
electr
ode junction
Bar
r
i
er
height (
e
V)
0.
63
0.
7
Ideality factor
1.004
1.02
(a)
(b
)
Evaluation Warning : The document was created with Spire.PDF for Python.
In
d
onesi
a
n
J
E
l
ec En
g &
C
o
m
p
Sci
ISS
N
:
2
5
0
2
-
47
52
Ba
ck-t
o
-Ba
c
k
S
c
ho
ttky Di
od
e fro
m
Va
cuum
Filte
red
and
C
h
emica
lly… (S
iti Na
d
i
ah
C
h
e
Azmi)
90
3
4.
CO
NCL
USI
O
N
Two
m
a
in
fab
r
ication
p
r
o
c
esses,
n
a
m
e
ly
v
a
cu
u
m
filtratio
n
and
L-AA ch
em
ical redu
ction
was
i
nvest
i
g
at
e
d
.
Go
fi
l
m
t
h
i
c
kness ca
n
be t
une
d t
o
s
o
m
e
ext
e
n
d
by
v
a
ry
i
ng
G
O
di
spersi
o
n
v
o
l
u
m
e
and
conce
n
t
r
at
i
o
n.
Vary
i
n
g
vol
u
m
e of
0.
4 p
p
m
di
spe
r
si
o
n
fr
o
m
50
m
l
t
o
20
0 m
l
resul
t
e
d i
n
fi
l
m
t
h
i
c
knes
s
fr
om
20 t
o
5
3
nm
. Next
, L-
A
A
re
d
u
ct
i
on
p
r
oces
s wi
t
h
di
ffe
rent
r
e
duct
i
o
n c
o
n
d
i
t
i
ons wa
s eval
uat
e
d.
The
red
u
ct
i
o
n
of
GO t
h
i
n
fi
l
m
i
s
foun
d t
o
b
e
rel
a
t
i
v
el
y
sl
ow p
r
oce
ss. L
o
n
g
re
duct
i
o
n t
i
m
e was re
qui
red
t
o
hi
g
h
l
y
red
u
c
e
t
h
e
GO
fi
l
m
. It
can
be c
oncl
ude
d t
h
at
re
duct
i
o
n a
f
t
e
r t
h
e
t
r
a
n
sfer
p
r
oce
ss m
a
y
pr
o
duce
hi
g
h
l
y
re
duce
d
G
O
fi
l
m
with
low sheet resistan
ce.
Fin
a
lly, th
e BBSD was
fab
r
i
cat
ed and its electrical characteristics was m
e
a
s
ure
d
.
From
t
h
e
obt
ai
ned
cu
r
v
e, t
h
e
rG
O/
Sch
o
t
t
k
y
j
unct
i
o
ns
p
o
sse
ss ba
rri
e
r
hei
g
ht
o
f
0.
6
3
a
n
d
0.
7 e
V
.
ACKNOWLE
DGE
M
ENTS
Thi
s
w
o
rk
has
been
su
p
p
o
r
t
e
d by
r
e
searc
h
uni
versi
t
y
g
r
a
n
t
(
0
3
G
22 a
n
d
13J
8
3
) a
n
d F
u
n
d
am
ent
a
l
R
e
search
Gra
n
t
Schem
e
(4F6
38
) o
f
M
i
ni
st
ry
of E
d
ucat
i
o
n
,
M
a
l
a
y
s
i
a
. S.N.
C
.
Azm
i
t
h
ank
s
M
i
ni
st
ry
of
Hi
g
h
er
Ed
ucat
i
o
n
f
o
r
f
i
nanci
a
l
s
u
p
p
o
r
t
du
ri
n
g
her
M
a
st
er p
r
og
ram
.
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Evaluation Warning : The document was created with Spire.PDF for Python.
I
S
SN
:
2
502
-47
52
I
ndo
n
e
sian
J Elec Eng
& Com
p
Sci, V
o
l. 10
,
No
.
3
,
Jun
e
2
018
:
89
7 – 90
4
90
4
BIOGRAP
HI
ES OF
AUTH
ORS
Siti Nadiah Che Az
mi
is currently
doing h
e
r Master
of P
h
ilosph
y
degr
ee in
Electr
ical
Engine
ering at Facul
t
y
of El
ec
tri
cal Engin
eer
i
ng,
Universiti Tekn
ologi Mala
ysia
,
Mala
y
s
ia
. She
has completed h
e
r Bach
elor of
Applied Scien
c
e
(Electronics an
d Instrumentatio
n Phy
s
ics) from
Universiti
Mala
ysia T
e
rengg
anu,
Malay
s
ia at 201
3.
Shahar
i
n F
a
d
z
li Abd Rahma
n
is
a s
e
nior l
ectur
er in F
acu
lt
y of El
ec
tric
a
l
Engine
ering
,
Universiti Tekn
ologi
Mal
a
y
s
ia
, Mala
y
s
ia
.
He co
m
p
leted his B
a
c
h
elor of
Engine
e
r
ing degre
e
and
Master of Eng
i
neering f
r
om Hokkaido Univer
si
ty
, Japan
in 2
007 and 2009,
respectively
.
In
2013, he obtain
e
d Doctor of Philosoph
y
in E
l
ectr
i
cal Engin
e
ering from
Univ
ersiti T
e
knologi
Malay
s
ia, Malaysia. His research
interest is semiconductor and
graphene-based electronic device
and sensor f
a
brication and
ch
aracter
i
zation
.
Abdul Manaf Hashim
is a professor at Malay
s
ia-Jap
an In
t
e
r
n
ation
a
l Institu
t
e
of Technolog
y,
Universiti T
e
kn
ologi Mala
ysi
a
.
He com
p
leted
hi
s Bachelor
of Engineer
ing and Master of
Engineering degree from Nagaoka University
of Technolog
y
,
Jap
a
n in 1997 and 1999,
respectively
.
He obtain
e
d his PhD degree in
Mar
c
h 2006 from Hokkaido Univers
i
ty
, Jap
a
n. His
areas of
exp
e
rtis
e and
specializ
ation includes s
y
n
t
hesi
s of semico
nductor n
a
nostru
c
ture and
thin
film using both liquid and v
a
por phase tec
hnologies, s
y
nthesis of graphene and carbon
nanotubes, plasma wave electr
onic devices, q
u
antum nanodevices, sensi
ng devices and solar
cel
ls
.
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