1. RICHU JOSE CYRIAC
M120128EC

5.  Exfoliation method

6.  Chemical vapor deposition
 Transition metal layers (e.g. Ir, Pd, Ni, Cu)
 Furnace to be heated to 1000º C in a hydrocarbon gas
 Catalyzes decomposition of hydrocarbon gas the dissociated carbon
atoms
 Later cooling, Carbon atom precipitates to surface and graphene is
formed.
 large area, high quality, controllable number of layers and low defects.

7.  Epitaxial growth
 Annealing of SiC crystal at a very elevated temperature (~2000 K) in ultra-high
vacuum.
 Thermal desorption of Si from the top layers of SiC.
 Time or temperature of the heating treatment is a limiting factor.

11.  A stationary particle (p=0) has rest energy
 A particle in motion is described by relativistic
dispersion relation
 Velocity:
222
)()( cpmcE
2
mcE
22
)()( cpmc
cp
c
dP
dE
v

12.  Massive particle(e.g. electron)
Non-relativistic limit(v‹‹c)
 Massless particle(e.g. photon)
....
2
2
2
m
p
mcE
0m
cv
pcE
222
)()( cpmcE

13.  Massless Dirac fermions: Charged massless particles
 Relativistic Quantum particles
 Spin directed only along the direction of propagation-
pseudospin
 A projection pseudospin on the direction of motion-
Chirality

14.  Weak electrostatic confinement.
 It cannot be used as a digital switch.

15.  Hetero atom doping
B and N –substitutional doping-similar atomic size
 Arc discharge
High current between graphene electrodes in presence of H2 + B2 H6 or
N2 + NH3
 Chemical vapour deposition
Cu film on silicon substrate as a catalyst in H2 atmosphere and
CH4+NH3
 Ion-irradiation
Defects are introduced through positive nitrogen ions and the samples
are annealed in NH3 . In the process of annealing defects are restored
,getting N doping

16.  Chemical modification process
 NO2 and NH3 creates holes and electrons respectively.
 Adsorption of water molecules-inexpensive, cheap, easier to
control-but performance degradation
 Organic molecules
Napthalalediamene – n doping
9,10-Dibromo anthracene- p doping
 Electrostatic field tuning

17.  Applying strain to graphene
 Biasing bilayer graphene

19.  Can achieve high speed in electronic devices,
which is transparent and flexible.
 As if now cannot be used as a digital switch owing
to Klein tunneling.
 Can be used in RF devices.
 It is surely a candidate material to replace silicon
in near future.

20.  The rise of Graphene, A.K. Geim and K.S. Novoselov
 The elementary electronic properties of Graphene, Qinlong Luo
 Graphene: carbon in two dimensions, Mikhail I. Katsnelson
 Graphene: Is It the Future for Semiconductors?An Overview of
the Material, Devices, and Applications, Yaw Obeng and
Purushothaman Srinivasan
 Graphene Doping: A Review ,Beidou Guo ,Liang Fang, Baohong
Zhang, Jian Ru Gong

21. T
H
A
N
K
Y
O
U

22.  Analytical description of π band
yyx
yyx
k
a
k
a
k
a
s
k
a
k
a
k
a
kE
2
cos4
2
cos
2
3
cos411
2
cos4
2
cos
2
3
cos41
)(
2
0
2
