graphene growth

Graphene GrowthJessica Patalano

Goals - Uniformity Fluid experiment (monolayer Cu balls and tubes)

Smoother surface Faster flow rate Less drag

Lithium-ion battery (multilayer Ni foils) Sandwiched between SEI and current collector Hold energy better 10x faster charge time

Goals - Uniformity Transmission Electron Microscopy grid (copper foil)

Instead of carbon evaporation

Done in high vacuum No water from biological sample can flow through Transparency allows electron flow

Process Initial cleaning – copper items

DI water, acetone, repeat Ammonium persulfate bath

Tubes Sonicate 30-45 minutes Electropolish ≈ 2 minutes

Initial cleaning – nickel items DI water, acetone, isopropanol

Process Pressure must be at 50 torr to open vacuum tube and mount sample

Samples must be dry

Flushing the system 100 sccm of methane for 10 minutes 100 sccm of hydrogen for 10 minutes 100 sccm of argon for 10 minutes

Process Oxide removal in furnace

35 sccm of hydrogen

Temperatures Nickel – 1000°C Copper - 1035°C

Cooking times Foils and nickel foam: 70 minutes Copper tubes and ball: 50 minutes

Process – Methane Exposure Ni foil (few layer)

CH4/H2 – 35/2 sccm 30 minutes

Ni foam CH4/H2 – 35/2 sccm 5 minutes

Nickel foil and foam

20x 20x

Process – Methane Exposure Copper balls and tubes

CH4/H2 – 40/15 sccm

30 minutes

Copper ball and tube control

Before cleaning

After Process, 20x Tube,

20x

Copper ball and tube with graphene?

Tube, 100x

Ball, 20x

Tube, 20x

Process – Methane Exposure Monolayer Graphene on Cu foil

CH4/H2 – 35/2 sccm 30 minutes

Bilayer Graphene on Cu foil CH4/H2 – 16/70 sccm 120 minutes

Future Projects

Confirm graphene growth on Cu tubes and balls

Additional samples of each item – more data

Improved uniformity on foils