7.01 Roll-To-Roll Graphene TransferSep 07, 2016  · • Graphene is nearly transparent, ultra strong and has an extremely high carrier mobility • This makes it a promising material

7.01 Roll-To-Roll Graphene Transfer

microsystems technology laboratories

Marek Hempel, Jing Kong, Tomas Palacios, marekh@mit.edu

Department of Electrical Engineering and Computer Science, Massachusetts Institute of Technology

Transferring CVD Graphene onto Flexible Substrates by

Hot Lamination and Electrochemical Delamination

1. Goal and Applications:

Use graphene to make flexible, conductive and transparent electrodes

• Needed for optoelectronic and wearable applications, for example:

2. Background:

• Graphene is nearly transparent, ultra strong

and has an extremely high carrier mobility

• This makes it a promising material to use as

transparent conductive electrodes

• Large areas can only be synthesized by

chemical vapor deposition (CVD) on Cu foil

8. Acknowledgement:

This project was funded by eni-MIT Solar Frontiers Center.

3. Approach:

• Use pressure and heat to

laminate graphene to target

• Separate by hydrogen

bubbles (use electrolysis)

5. Metrology:

• Molding of copper foil texture

highly visible on EVA

• Dark field microscopy (DF)

helps to visualize features

Touch ScreensSmart Windows Solar Cells Displays

Challenge is to transfer graphene in a scalable way and with high quality

4. Implementation:

Lamination

• Use EVA coated PET as substrate

• Temp. range of heat shoes: 90°– 250°C

• Speed range of DC motors: 0.7 – 5 mm/s

• Roller pressure ranges from: 0 – 400 N

Delamination

• Use sodium chloride (NaCl) or sodium

hydroxide (NaOH) as electrolyte with 0.5 mol/l

Hot laminationElectrochemical

Delamination

6. Electrical Characterization and Doping

7. Repeated Lamination and Delamination

DF 100x

477.1175.7

4568.3

761.1

0

1000

2000

3000

4000

5000

G on SiO2 G on SiO2doped

G onPET/EVA

G onPET/EVA

doped

avg

. sh

eet

resis

tan

ce [Ω

/□]

1E+11

1E+12

1E+13

1E+14

200 2000Carr

ier

co

ncen

trati

on

[cm

-2]

mobility [cm2/Vs]

1L 1L doped

2L 2L doped

10000

10µm

1E+11

1E+12

1E+13

1E+14

200 2000

Carr

ier

co

ncen

trati

on

[cm

-2]

mobility [cm2/Vs]

G on SiO2G on PET/EVAG on SiO2 dopedG on EVA/PET dopted

10000

1L 1L

doped

2L 2L

doped

sh

eet

resis

tan

ce [

kΩ

/□]

6.0x

4.9x

3.4x

6

5

4

3

2

1

0

• Stacking 2 graphene

layers improves

conductivity by 3.4x

• This is more than

expected increase of

factor of 2x

All rights reserved by Hempel, et al. Reproduced here with permission for educational purposes only.