rgdfggvgfgdsdcchjbff

1. Graphene: Production, Properties and Applications
Presented By: Ardalan Hayati Far
1

2. Carbon allotropes
Carbon
forms/
Hybridization
sp3
sp2
sp
sp3
- sp2
2

3. Carbon allotropes
•sp3
QuickTime™ and a
GIF decompressor
are needed to see this picture.
The Darya-I-Nur Diamond Unit cell of the diamond cubic crystal structure
3

4. Carbon allotropes
•sp
( C C )− ≡ − n
4

5. Carbon allotropes
•sp3
-sp2
5

6. Carbon allotropes
•sp2
Graphite
Fullerene
Graphene
6

7. 7

8. Graphene and its descendants
8

9. Production Techniques
• Exfoliation
• Epitaxy
★ Silicon carbide
★ Metal substrates
9

10. Production Techniques
• Exfoliation
10

11. Production Techniques
• Exfoliation
Graphene on SiO2
Graphene suspension in
chloroform11

12. Production Techniques
• Epitaxy Metal substrate
12

13. Production Techniques
• Epitaxy Silicon carbide
13

14. Properties
• Structure
• Mechanical
• Chemical
• Optical
• Thermal and thermoelectric
• Electronic
14

15. Properties: Structure
TEM Optical micrograph
15

16. Properties: Mechanical
Pressure strengh AFM
16

17. Properties: Chemical
NO2 molecule on graphene surface
17

18. Properties: Optical
18

19. Properties:Thermal and
thermoelectric
19

20. Properties: Electronic
Why graphene is strange?
Electrons in graphene = Charge carriers
Electrons in graphene have zero effective mass.
For graphene we use Dirac equation! not Schrodinger
equation.
20

21. Properties: Electronic
Graphene lattice Band structure diagram
21

22. Band structure diagram
Chemist Physicist
Localized electrons Delocalized electrons
MO Diagram Band Structure Diagram
Molecular Orbital Wavevector
Chemical bonding Potentials
Qualitative (Intuitive) Quantitative (Mathematical)
22

23. Band structure diagram
Bloch function
23

24. Band structure diagram:
An example
The Band Structure of a 1D chain of H atoms
24

25. Graphene Band
Structure
High symmetry points25

26. Graphene Band
Structure
26

27. Graphene Band
Structure
27

28. Graphene Band
Structure
28

29. So What?!
Graphene is a gapless semiconductor.
Graphene is a metal without overlapping.
Richard Feynman 29

30. 30

31. Applications
Visit this link:
http://www.graphene.manchester.ac.uk/future/
31

32. 32
Thanks for your attention
Questions?
Ardalan Hayati Far
Dey 1392