Electronic Properties
of Nano-Carbon Systems
Carbon Nanotubes Graphene
Intercalated Graphite Networks
Individual Wires Siegmar Roth
s.roth@fkf.mpg.de
Lecture 4
24th March 2009
a) “Bsic Solid State Physics”
b) “Devices based on
Individual Carbon Nanotubes”
Format of future lectures?
Basics in the morning?
(9:00 to 10:30?)
Research Report in the evening?
(17:00 to 18:00? = 09:00 – 10:00?) (18:00 to 19:00?)
(19:00 to 20:00?)
Evening lecture would allow
Europeans to attend via internet
Basics:
How would we organize the exams?
a)Midterm:
5 to 10 topics out of a list, write a few lines to each of the topics, but enough to convince me that you understand the matter
b) Endterm: again 5 to 10 topics from the list + a short oral discussion
Topics List for Siegmar’s Lectures 1.) What is a crystal?
2.) Why are crystals so important for solid state physics?
3.) What is special with nanocrystals?
4.) Crystal lattice, elementary cell 5.) Reciprocal lattice
./.
Topics List for Siegmar’s Lectures 6.) Particle-wave-dualism
7.)Electrons in a solid 8.) Bloch Waves
9.) Density of States 10.) Fermi Level
11.) Energy Bands, Electrons, Holes, Doping
12.) Energy Gap 13.) Electron Spin
./.
Topics List for Siegmar’s Lectures 14.) Drude Model
15.) Drift Velocity 16.) Mobility
17.) Ballistic Transport 18.) Hall Effect
19.) Quantum Hall Effect 20.) Magnetoresistance
21.) Thermoelectric Effect 22.) Ideal Conductivity
23.) Superconductivity
./.
Topics List for Siegmar’s Lectures 24.) Carbon
25.) Graphite 26.) Diamond 27.) Graphene 28.) Nanotubes 29.) Fullerenes 30.) Peapods 31.) Polymers
32.) Conjugated Polymers 33.) Polyacetylene
34.) Conducting Polymers ./.
Topics List for Siegmar’s Lectures 35.) Composites
36.) Nanocomposite 37.) Percolation
38.) Transparent Conducting Films 39.) Microwave Attenuation
40.) Actuators
41.) Nanosensors 42.) Field Emission
./.
Topics List for Siegmar’s Lectures 43.) Supercapacitors
44.) Batteries with Nanotubes 45.) Fuel Cells
46.) Electrochromic Devices 47.) Solar Cells
48.) Thermoelectric Energy Harvesting 49.) …..
50.) …..
./.
200nm Long, very straight tubes => well suited for El. Diffraction 50nm
1 SWNT, with contacts
Devices based on
Individual Carbon Nanotubes
Minimum Knowledge:
Single-Walled Multi-Walled
Semiconducting Metallic
What are Nanotubes?
The Price of 1 Nanotube:
1 tube contains about 10**5 atoms
12g --- 10**23 atoms --- 10**18 tubes 1g --- 1k € --- 10**17 tubes
1 tube costs about 10 f€
AFM image of SWCNT over gold leads on Si chip, representing a „conventional“
carbon nanotube transistor
Schematic view of
„conventional“ Carbon Nanotube Transistor
Transistors
Three Terminal Device Source, Drain, Gate
Active Channel, Gate Dielectric Output Characteristics
Transfer Characteristics
Singel Electron Transistors
Coulomb Blockade V = Q / C
V … Voltage [Volts]
Q … Charge [Coulomb]
C … Capacitance [Farad]
E = ca. 10-19 Coulomb
C = 10-18 Farad (single nanotubes) Æ V = ca. 1 eV (Electronvolt)
Sensors
Sensitivity Selectivity
Reproducibility Calibration
Self-Learning Systems ?
Output Characteristics of CNT Transistor at various gate voltages
„All-Carbon“ Transistor
Wet-chemical synthesis of nanotube junctions
0.0 0.2 0.4 0.6 0.8 1.0 0
100 200
G 12 (nS)
carbon gate (mV)
Change of channel conductance as function of voltage at carbon gate
-0.2 -0.1 0.0 0.1 0.2 0.0
0.5 1.0 1.5 2.00 20 40 60 80 100 0 50 100 150 200 250
-0.80 -0.4 0.0 0.4 0.8 40
80
0 2 4 6 8 10
10-12 10-11 10-10 10-9 10-8
(d)
(e)
(f) (c)
G 12 (nS)
back gate (V)
(b)
G 12 (nS)
(a)
G 12 (nS) G12 (nS)
back gate (V)
carbon gate = 0.4 mV
carbon gate = 1 mV carbon gate = 0
α Eg G12 (S)
back gate (V)
Introduction of insulating barrier into metallic tube by application of voltage to carbon gate
Dy@C82
(Dy@C82)n@nanotube Dy atom
Metallofullerene Peapod
TEM of (Dy@C-82)@SWCNT
Nanotube peapod FETs
0 200 400 0 200 400
(b) 265 K
300 K (a)
G (nS)G (nS)
-10 -5 0 5 10
0 25 50 75 100
(c)
215 K
42 K 75 K 100 K
4 K 11 K
G (nS)
VG (V) Vds
n++ Si
SiO2
Vgs
Drain Source
Gate Voltage
Spin Valve
29.05.07 Strasbourg s.sahakalkan@fkf.mpg.de
R
A H
Co Co
Vg
Vsd
CIA = Current-Induced Annealing
Vertical Nanotube Transistor (Patented by Infineon
- and by Samsung ?!)
C
Battery of Nanotube Transistors (Infineon)
Vias from Nanotube Bundles (Cooperation with Infineon)
(BMBF „INKONAMI“ mit Infineon)
BMBF
„INKONAMI“
Infineon
