Applications of Graphitic Carbon Materials
Dr. Lain-Jong Li (Lance Li)
Associate Research Fellow
Research Center for Applied Science
Academia Sinica, Taiwan
Frontier NanoCarbon Research group
Research Center for Applied Sciences, Academia Sinica
Single-Walled Carbon Nanotubes
for Macroelectronics
Frontier NanoCarbon Research group
Research Center for Applied Sciences, Academia Sinica
1. Transistors based on carbon nanotube networks
Solution processable
Printable
( Adv. Mater. 2010)
(Chem. Comm. 2009)
Frontier NanoCarbon Research group
Research Center for Applied Sciences, Academia Sinica
2. Carbon Nanotube Networks as DNA sensors
1. Devices are fabricated by microelectronic fabrication.
2. DNA addition directly affects the transfer characteristics
3. Detection limit: ~ 10 nM DNA
Normalized Current Id ()
100
(a)
Bare
bare device
immobilization
hybridization
intercalation
80
60
Immobilized40
Hybridized
20
Intercalated 0
-10
-5
0
Vg (V)
Frontier NanoCarbon Research group
Phys. Lett.
89, 232104
(2006)
Research Center for Applied Appl.
Sciences,
Academia
Sinica
5
10
2.1 Study of Sensing Mechanism
Changing the contact metals
Frontier NanoCarbon Research group
Research Center for Applied Sciences, Academia Sinica
Covering the contacts
SWNT channels slightly response to DNA molecules
But electrode-SWNT Contacts seem to play more important roles
( J. Am. Chem. Soc. 129, 14427, 2007)
Frontier NanoCarbon Research group
Research Center for Applied Sciences, Academia Sinica
2.2 Introducing more charges
More charges can be introduced to the DNA with reporter DNA
Frontier NanoCarbon Research group
Research Center for Applied Sciences, Academia Sinica
Sensitivity enhancement
The DNA detection limit is dramatically improved from 1 nM to 100 fM
by using reporter DNA-AuNP conjugates
( Adv. Mater.
20, 2389, 2008)
Frontier NanoCarbon Research group
Research Center for Applied Sciences, Academia Sinica
Graphene-related
Frontier NanoCarbon Research group
Research Center for Applied Sciences, Academia Sinica
1. Large Size Graphene Oxides
Ultra-large single layer graphene oxides
( up to mm size)
( absorption ~ 2%)
Chem. of Mater. 21, 5674 (2009)
Frontier NanoCarbon Research group
Research Center for Applied Sciences, Academia Sinica
2. Graphene Oxide Reduction by Alcohol
* 1st stage: I(D) increases with richness of 6-fold aromatic rings
* 2nd stage: I(D) is inversely proportional to the graphene domain
size (T-K relations)
Frontier NanoCarbon Research group
Research Center for Applied Sciences, Academia Sinica
Graphene Oxide Reduction by Alcohol
* Graphene domain size is dominating conduction properties
(submitted)
Frontier NanoCarbon Research group
Research Center for Applied Sciences, Academia Sinica
3. CVD Graphene
Pressure: 0.1~1 Torr and 750 Torr on Cu and Ni substrates respectively.
Step 1: H2
Step 2: H2
Step 3: CH4/H2
Step 4: Ar
900 ºC
Substrate: Ni foil,
30 μm in thickness
RT
1
2
3
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4
30 min
30 min
10~20 min
Research Center for Applied Sciences, Academia Sinica
Transfer to the desired substrates
(a)
FLG
Cu foil
FLG
Immerse FLG/Cu foil
in ~ 1.5 wt% FeCl3 solution
Rub one side FLG
by sandpaper
FLG
Cu foil
FLG
Cu foil
FeCl3 solution
FLG
New Substrate
Heat at 80 0C
for 5-10 minutes
Wait for several hours
Dilute FeCl3 solution and
transfer to new substrate,
such as PET, SiO2
FLG
(b)
FeCl3 solution
FLG
Frontier NanoCarbon Research group
Research Center for Applied Sciences, Academia Sinica
4.1 Doping of Graphene from Substrates
Charge exchange may occur between graphene and SiO2
Effective
doping in graphene
monolayer
SiO2 NanoCarbon Research group
Frontier
Research Center for Applied Sciences, Academia Sinica
Doping of Monolayered graphene depends
on the surface potential of SiO2 substrates
Phys. Rev. B
79, 115402 (2009)
Frontier NanoCarbon Research group
Research Center for Applied Sciences, Academia Sinica
4.2 Doping of Graphene by Aromatic Molecular
Adsorption
Small 5, 1422 (2009)
Frontier NanoCarbon Research group
Research Center for Applied Sciences, Academia Sinica
4.3 Stable Doping of CVD Graphene by AuCl3
Work Function is Tunable
Frontier NanoCarbon Research group
Research Center for Applied Sciences, Academia Sinica
Work function
Frontier NanoCarbon Research group
Research Center for Applied Sciences, Academia Sinica
Work function is tunable
ACS Nano (2010 in press)
Frontier NanoCarbon Research group
Research Center for Applied Sciences, Academia Sinica
5. Aromatic molecules on Graphene
Tetrasodium 1,3,6,8-pyrenetetrasulfonic acid (TPA)
Strong electron-withdrawing groups attached to pyrene
Frontier NanoCarbon Research group
Research Center for Applied Sciences, Academia Sinica
Phonon Symmetry Breaking- DFT calculation
a full geometry optimization is performed including the optimization of the lattice
constants using the DMol3 package (with all electrons considered) and the GGA
(PBE) and DNP basis sets. Once the optimized structure is obtained, the force
constants are calculated directly by altering atomic positions in both pristine and
decorated graphene. ( ~4% different from those in pristine graphene)
*Various aromatic molecules result in different energies of G-band splitting.
Phys. Rev. Lett. 102, 135501 (2009)
Frontier NanoCarbon Research group
Research Center for Applied Sciences, Academia Sinica
Ongoing study
1.
Gap Opening: Stripping ?
AB-stacked bilayer graphene ?
How to grow bilayer graphene with desired stacking
2.
Effect of defects on transport?
3.
Effect of graphene edge (or edge defect)?
Frontier NanoCarbon Research group
Research Center for Applied Sciences, Academia Sinica