1. Graphene A short summary
Patrik Thuiner

2. Goal
Create a device fully transparent to electrons and fully opaque to ions e-
CO2+
Ar+

3. Sample preparation / graphene transfer1 2 3 ?
Find “good” side of copper foil
Etch away “bad” layer in nitric acid
Spin-coat with PMMA
Etch away copper foil with Fe 3 nitrate
PMMA with graphene layer on bottom floating on Fe 3 nitrate
First step of cleaning with demineralized water
Second step of cleaning with demineralized water
PMMA with graphene on bottom scooped out with mesh/GEM
PMMA dissolved with acetone in Critical Point Dryer
Nitric Acid 4 5 6
Iron 3 Nitrate
Iron 3 Nitrate
Demineralized Water 7 8 9
Acetone
Demineralized Water
Demineralized Water

4. Single-layer graphene on copper mesh
Coverage in the order of 70-95% e-
Defects
CO2+
Ar+

5. Triple-layer graphene on copper mesh
Coverage in the order of 99.9% Contaminations between layers? e-
CO2+
Ar+

6. Triple-layer graphene on GEM bot electrode
field focussing
kΩ to MΩ
Coverage in the order of 99.9%
Short between electrodes on all samples so far
Probably due to graphene sample borders
pre-acceleration
transmission

7. New GEM layout
active area
YES!
YES!
NO!

8. Graphene samples and transfer
Previous samples
New samples
Supplier
Graphene Supermarket
Advanced Graphene Products
Single-layer samples
Single-layer graphene on copper
(5cm x 5cm)
Single-layer High Strength Metallurgical Graphene™ on PMMA (1cm x 1cm)
Multi-layer samples
Single-layer transferred onto another single-layer, onto another…
Directly grown multi-layer
Graphene transfer
Cutting to smaller sample size
Spin-coating with PMMA Etching of copper Transfer onto support Removal of PMMA
Transfer onto support Removal of PMMA
Support structure
GEM-like copper mesh standard GEM, 3cm x 3cm
New GEM, 0.5cm x 0.5cm area