Graphene Nanoribbons

1. Graphene Nanoribbons
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Presented to: Rethwan Faiz
Course name: Digital Electronics
Section: [C]
Presented By:
SOAIBUZZAMAN 14-
28039-3
NONGMEIKAPAM YURREINGAM 14-
28013-3
AFSER FAHIM 14-
28008-3
Tahsin Samiha Promi 14-
xxxxx-3

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 Graphene
 Carbon nanotubes (CNT)
 Graphene nanoribbons (GNR)
 Comparison between CNT and GNR
 Synthesis methods of GNRs
 Applications of GNRs
 Op amp circuit using CNTFET

3. •GRAPHENE IS A ONE-ATOM-THICK PLANAR SHEET OF SP2-BONDED CARBON
ATOMS THAT ARE DENSELY PACKED IN A HONEYCOMB CRYSTAL LATTICE
• THE NAME ‘GRAPHENE’COMES FROM: GRAPHITE + -ENE = GRAPHENE
Molecular structure of graphene
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pure substance, orderly structure based on tight, regular, atomic
bonding
Graphene is believed to be the strongest material yet
discovered
Has high thermal conductivity
 Can conduct electricity very well
Is very light and transparent
Sheets of Graphene are impermeable

5. Graphene is the basic structural element of some carbon
allotropes including…
 Graphite
 Charcoal
 Carbon Nanotubes
 Fullerene
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Carbon nanotubes (CNT) are basically graphene sheets rolled
up in a certain direction.
“Chiral vector” or “chirality” describes how a graphene sheet
is rolled up to form CNT.
CNT might be metallic or semiconducting, depending on its
chirality.
Carbon nanotubes are strong, they are not brittle.
They can be bent, and when released, they will spring back to
their original shape.

7. A carbon nanotube with openends
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A carbon nanotube with closedends

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also called nano-graphite ribbons
carbon based material
one-dimensional structures with hexagonal two dimensional
carbon lattices
a derivative of Graphene
Graphene ribbons were introduced as a theoretical model
by Fujita

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GNR inherits almost all the attractive properties of the carbon
nanotube and graphene.
Has additional benefit of a tunable band gap
Zigzag & Armchair GNRs have metallic or semiconducting
electronic properties that depends on the width of the
nanoribbon.

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A CNT MolecularStructure A GNR MolecularStructure

12. 12A CNT UnitCell A GNR UnitCell

13. Rolling of a Carbon nanotube (CNT)
from a graphene sheet
Cutting of a graphene
nanoribbon (GNR) from a sheet
of graphene
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The structure and physical properties of GNRs vary significantly
depending on the synthesis method. The methods are:
Cutting from graphene using lithography
 Bottom-up synthesis from polycyclic molecules
Unzipping of carbon nanotubes (CNTs)

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Light emitting diodes
P-N junctions
Schottky diodes
Field effect transistors
Conductive electrodes
Solar cell systems
Field effect transistors

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