2009.2.12. QMMRC-IPCMS Synthesis and Applications of Large-Scale Graphene Films Synthesis and Applications of Large-Scale Graphene Films Large Scale Graphene Films Byung Hee Hong Large Scale Graphene Films Byung Hee Hong Department of Chemistry and Sungkyunkwan Advanced Institute of Nanotechnology (SAINT), Sungkyunkwan University, 2009.2.12. QMMRC-IPCMS Toward All-Graphene Electronics Replacing Si-based Semiconductor Technology? Theory Band-gap Engineering Edge Control Q t T t Nanoscale Devices Quantum T ransport Transistors Large-scale Transparent Flexible Electrodes All graphene Circuit Devices All graphene Circuit 2009.2.12. QMMRC-IPCMS Background Background Transparent? No YES 2009.2.12. QMMRC-IPCMS Non-Flexible Electronics
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2009.2.12. QMMRC-IPCMS
Synthesis and Applications ofLarge-Scale Graphene Films
Synthesis and Applications ofLarge-Scale Graphene FilmsLarge Scale Graphene Films
Byung Hee Hong
Large Scale Graphene FilmsByung Hee Hong
Department of Chemistry and Sungkyunkwan Advanced Institute of Nanotechnology (SAINT), Sungkyunkwan University,
(A) Precise cutting of SWNTs with an oxygen plasma introduced through an opening in a window of PMMA defined with e-beam lithography.
(B) The results of oxidative opening of the tubes are point-contacts that are functionalized on their ends with carboxylic acids and separated by as little as 2 nm
(C) Scanning electron micrograph of a SWNT with Au on Cr leads that had been cut i b li h h d l using e-beam lithography and oxygen plasma.
(D) AFM image of the gap cut into the SWNT. Inset: height profile of the isolated tubes. The diameter of the SWNT is 1.6 nm, estimated from the height profile.
čatalyst: 6rop-dried Fečl3 0.05M solution in water
Furnace lenčt5: 30cm / Growt5 time = ~3 5rs
The maximum length is limited by the size of the substrate and the length of the furnace rather than termination of growth!
2009.2.12. QMMRC-IPCMS
Room-Temperature Ballistic Transport in CNTCNTs
Multi-terminal Device with Pd contactcontact
* Scaling behavior of resistance: ì(L)
Scaling of Resistance and Electron Mean Free Path of Single-Walled Carbon NanotubesM. Purewal, B. H. Hong, A. Ravi, B. Chandra, J. Hone, and P. Kim, Phys. Rev. Lett, 98, 186808 (2007).
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Rise of Graphene
I. Introduction
T di i l f l Di f i i h
Rise of Graphene>300 SCI papers every year since 2006
Two-dimensional gas of massless Dirac fermions in graphene Novoselov, KS; Geim, AK; Morozov, SV, et al.NATURE Volume: 438 Issue: 7065 Pages: 197-200 Published: NOV 10 2005 Times Cited: 1080Times Cited: 1080
Experimental observation of the quantum Hall effect and Berry's phase in Experimental observation of the quantum Hall effect and Berry s phase in graphene Zhang, YB; Tan, YW; Stormer, HL, et al.NATURE Volume: 438 Issue: 7065 Pages: 201-204 Published: NOV 10 2005 gTimes Cited: 970
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Wh G h ?
I. Introduction
Why Graphene ?
High mobility(~10,000 cm2/Vs @RT).Superb heat conductor.Superb heat conductor.High current densities(~108 A/cm2).Transistors based on ribbons.Chemical StabilityMechanical FlexibilityQuantum Electronic TransportQuantum Electronic Transport
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Graphene Electronics I. Introduction
Replacing Si-based Semiconductor Technology?
All G h El t iAll G h El t iAll Graphene ElectronicsAll Graphene Electronics
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All Graphene Electronics I. Introduction
Replacing Si-based Semiconductor Technology?
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Electric Field Effect in Electric Field Effect in Atomically Thin Carbon Film
Science 306, 666 (2004)
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2D gas in Quantum Limit: Conventional Case2D gas in Quantum Limit: Conventional Case
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Quantum Hall Effect in GrapheneQuantum Hall Effect in Graphene
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Graphene Nanoribbons: Confined Dirac Particles
I. Introduction
Graphene Nanoribbons: Confined Dirac Particles
2009.2.12. QMMRC-IPCMS
No structural edge effect
I. Introduction
No structural edge effect in e-beam patterned GNRs
Edge-control is essential for practical applications.g p pp
Characterization Method – FT-IR L S l d dLarge Samples needed.
2009.2.12. QMMRC-IPCMS
Disordered Edge Structures of Graphene
Nature Nanotechnology 3, 3č7-401, (2008)
2009.2.12. QMMRC-IPCMSI. Introduction
Problems
- The scale of graphene layers are too small for practicalapplications.
Large-scale Synthesis and Transferring Methods
- The rough edge structure of graphene blocksthe band-gap engineering of graphene nanostructuresthe band-gap engineering of graphene nanostructures.
Controlling Edge Structures by Wet Chemistryg g y y
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Edge Structures of
I. Introduction
Edge Structures of Graphene
H H H H H H H HHH
zigzag edgeStructural EdgesH H H H
H N
H
H H H
H
HHH
H
H
HH
H
OH hydroxyl
H
H
HH
H
H
N
O
OH
H
H
Hamino
carboxyl
O
H
HH
H
H H
H
H
HH
aceto
alkylH H H
N OO
H
HHH H H H H
a y
nitroChemical Edges
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Higher Charge Density
I. Introduction
Higher Charge DensityOf Graphene Edges
Nano Lett 7, 2295 (2007)
2009.2.12. QMMRC-IPCMS
Band Gap Modulation by I. Introduction
Chemical modification of zigzag
Chemical Modification of Zigzag EdgesChemical modification of zigzag ribbons can break the spin degeneracy, resulting in the onset of a semiconducting-metal transition a semiconducting metal transition, while it doesn't affect much for armchair edge modification.
Phys. Rev. B 77, 165427 (2008) , arXiv:0711.1700
2009.2.12. QMMRC-IPCMS
II. Graphene Synthesis/Manipulation
Origin of Mechanical Property
- Mechanical Approach
- Origin of Mechanical Property
Mechanical Approach
- Chemical Approachpp
2009.2.12. QMMRC-IPCMS
Mechanical Properties of GrapheneMechanical Properties of GrapheneII-1. Origin of Mechanical Property
V SummaryV. Summary-We have developed a simple method to grow and transfer hi h lit t t h bl h fil i ti t l high-quality stretchable graphene films in centimeter scale utilizing CVD on Ni layers.
-The patterned films can be easily transferred to t t h bl b t t b i l t t th d d th stretchable substrates by simple contact methods and the
number of graphene-layers can be controlled by the thi k f t l ti t l th ti f UV t t tthickness of catalytic metals or the time of UV treatment.
Th t t di ti l l t i l d ti f th - The outstanding optical, electrical and properties of the graphene films enable numerous applications to fl ibl / t t h bl /f ld bl l t iflexible/stretchable/foldable electronics.
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A k l d tAcknowledgement
– Sungkyunkwan University• Dr. Keun Soo Kim, Jung-Hee Han, Jin-Ho Kim, Hoosung Lim, g , , g• Profs. J.H. Ahn,
– Samsung Advanced Institute of Nanotechnology• Dr. Jae Young Choi
– Columbia University• Prof Philip Kim• Prof. Philip Kim
– POSTECH• Prof. Kwang S. Kimg• Dr. Chan-Cuk Hwang