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Frontier NanoCarbon Research groupResearch Center for Applied Sciences, Academia Sinica
Applications of Graphitic Carbon Materials
Dr. Lain-Jong Li (Lance Li)Associate Research Fellow Research Center for Applied ScienceAcademia Sinica, Taiwan
Frontier NanoCarbon Research groupResearch Center for Applied Sciences, Academia Sinica
Single-Walled Carbon Nanotubes for Macroelectronics
Frontier NanoCarbon Research groupResearch Center for Applied Sciences, Academia Sinica
Solution processable
Printable
( Adv. Mater. 2010)(Chem. Comm. 2009)
1. Transistors based on carbon nanotube networks
Frontier NanoCarbon Research groupResearch 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 characteristics3. Detection limit: ~ 10 nM DNA
-10 -5 0 5 100
20
40
60
80
100
Nor
mal
ized
Cur
rent
Id
(
)
Vg (V)
bare device immobilization hybridization intercalation
(a)Bare
Immobilized
Hybridized
Intercalated
Appl. Phys. Lett. 89, 232104 (2006)
Frontier NanoCarbon Research groupResearch Center for Applied Sciences, Academia Sinica
Changing the contact metals
2.1 Study of Sensing Mechanism
Frontier NanoCarbon Research groupResearch Center for Applied Sciences, Academia Sinica
Covering the contacts
SWNT channels slightly response to DNA moleculesBut electrode-SWNT Contacts seem to play more important
roles
( J. Am. Chem. Soc. 129, 14427, 2007)
Frontier NanoCarbon Research groupResearch Center for Applied Sciences, Academia Sinica
More charges can be introduced to the DNA with reporter DNA
2.2 Introducing more charges
Frontier NanoCarbon Research groupResearch Center for Applied Sciences, Academia Sinica
The DNA detection limit is dramatically improved from 1 nM to 100 fM
by using reporter DNA-AuNP conjugates
( Adv. Mater. 20, 2389, 2008)
Sensitivity enhancement
Frontier NanoCarbon Research groupResearch Center for Applied Sciences, Academia Sinica
Graphene-related
Frontier NanoCarbon Research groupResearch Center for Applied Sciences, Academia Sinica
1. Large Size Graphene Oxides
Chem. of Mater. 21, 5674 (2009)
Ultra-large single layer graphene oxides
( up to mm size)( absorption ~ 2%)
Frontier NanoCarbon Research groupResearch Center for Applied Sciences, Academia Sinica
* 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)
2. Graphene Oxide Reduction by Alcohol
Frontier NanoCarbon Research groupResearch Center for Applied Sciences, Academia Sinica
* Graphene domain size is dominating conduction properties
(submitted)
Graphene Oxide Reduction by Alcohol
Frontier NanoCarbon Research groupResearch Center for Applied Sciences, Academia Sinica
Substrate: Ni foil, 30 μm in thickness
Step 1: H2
Step 2: H2
Step 3: CH4/H2 Step 4: Ar
900 ºC
RT1 2 3 4
Pressure: 0.1~1 Torr and 750 Torr on Cu and Ni substrates respectively.
30 min 30 min 10~20 min
3. CVD Graphene
Frontier NanoCarbon Research groupResearch Center for Applied Sciences, Academia Sinica
FLG
FLGCu foil
Rub one side FLG by sandpaper
FLGCu foil
FLGCu foil
Immerse FLG/Cu foil in ~ 1.5 wt% FeCl3 solution
FeCl3 solution
FLG
FeCl3 solution
Wait for several hours
Dilute FeCl3 solution and transfer to new substrate, such as PET, SiO2
Heat at 80 0C for 5-10 minutes
(a)
(b)
FLG
FLGNew Substrate
New Substr
ateFLG
Transfer to the desired substrates
Frontier NanoCarbon Research groupResearch Center for Applied Sciences, Academia Sinica
4.1 Doping of Graphene from Substrates
Charge exchange may occur between graphene and SiO2
SiO2
Effective doping in graphenemonolayer
Frontier NanoCarbon Research groupResearch Center for Applied Sciences, Academia Sinica
Doping of Monolayered graphene dependson the surface potential of SiO2 substrates
Phys. Rev. B 79, 115402 (2009)
Frontier NanoCarbon Research groupResearch Center for Applied Sciences, Academia Sinica
4.2 Doping of Graphene by Aromatic Molecular Adsorption
Small 5, 1422 (2009)
Frontier NanoCarbon Research groupResearch Center for Applied Sciences, Academia Sinica
4.3 Stable Doping of CVD Graphene by AuCl3
Work Function is Tunable
Frontier NanoCarbon Research groupResearch Center for Applied Sciences, Academia Sinica
Work function
Frontier NanoCarbon Research groupResearch Center for Applied Sciences, Academia Sinica
Work function is tunable
ACS Nano (2010 in press)
Frontier NanoCarbon Research groupResearch Center for Applied Sciences, Academia Sinica
Tetrasodium 1,3,6,8-pyrenetetrasulfonic acid (TPA)
Strong electron-withdrawing groups attached to pyrene
5. Aromatic molecules on Graphene
Frontier NanoCarbon Research groupResearch Center for Applied Sciences, Academia Sinica
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)
Phonon Symmetry Breaking- DFT calculation
Frontier NanoCarbon Research groupResearch Center for Applied Sciences, Academia Sinica
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)?
Ongoing study