Epitaxial Graphene: a New Platform for Carbon ElectronicsEpitaxial Graphene: a New Platform for Carbon Electronics

Materials DevelopmentMaterials Development State of the ArtState of the Art Education and DiversityEducation and DiversityEducation and DiversityEducation and DiversityThe GT MRSEC has been developing techniques to fabricate new device architectures. An extensive network of both in house and external experts allow rapid analysis of transport and electronic properties through a wide variety of experimental techniques.

Goal: To equip a diverse population of students with the technical and professional tools needed to lead the science and engineering communities of tomorrow in industry, academia, and the public.

Device architecture

A

B

B

A

I(k)

(a.

u.)

3rd cone

Band structure of multilayer graphene

Thickness Map Chip Size: 3.5mm×4.5mm Average Thickness: 8.08 ÅStandard Deviation: 0.46Å

Graphene is grown in a high pressure furnace that leads to extremely well order films.

C-Face termination

Si-Face termination

SiC

INTRODUCTIONINTRODUCTIONThe GT MRSEC consist of a single IRG whose goal is to develop epitaxial graphene as a new material for the post Si-CMOS age. Research focuses on the growth of graphene on SiC, characterizing both its structural and electronic properties and a vigorous push to develop device architectures and fabrication processing to bring graphene as quickly as possible to a commercial stage.

Epitaxial graphene is the only commercially relevant production method. It is produced by Si sublimation from SiC, which leads to thin film graphene on insulating SiC.

Graphene is a single sheet of graphite. Its electronic band structure near the Fermi Energy is unique. The linear bands mean that the electron effective mass is essentially zero!

•Scalable to large circuit arrays•Extreme mobilities (>105cm2/V-sec)•Ambipolar doping by an applied field•High current capacity• Predicted THz switching speeds

High PT FurnaceSTM of

Graphene

Si-Face

C-face

C-face graphene is a new allotrope of carbon. Rotational stacking order makes nearly all sheets in the stack behave electronically like an isolated graphene sheet.

graphite Multilayergraphene

(a) Schematic graphene ribbon array and buss (grey) on a 4 x 6mm SiC Sample. (b) a blowup SEM image of the graphene ribbon array. (c) a SEM blowup of (b) showing 11nm graphene ribbons.

Eg ~ 0.1eV EDC through the Dirac point for 20nm ribbons. Dashed line is data for after dividing by the Fermi-Dirac distribution at 300K.

N02

Chemical Functionalization

Thermal potential measurement structure

E=20-50 V/K

n=0

n=1

n=3

4µm

n=2

Quantum Hall Effect in graphene ribbons

For Room Temperature

resistance standards

Hall bar structureFor mobility and doping

measurements

GateSource

Drain

1m graphene ribbon channel

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Research Experience for Undergraduates

• 10 weeks of EG research• Each student has both a faculty advisor

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and a travel allowance• Visits to local industrial sites• Social and cultural activities

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