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

Monolayer Graphene Much easier because of the nature of the material

Bilayer Graphene (thickness < 1 nm) Gas-sensing properties Could be better at managing heat of high-power electrical devices Appropriate number of layers balances electrical conductivity with

transparency

Process

Initial cleaning – copper items DI water, acetone, repeat Ammonium persulfate bath

Tubes – sonicate, then electropolish

Initial cleaning – nickel items DI water, acetone, isopropanol

Process

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

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

Process – Methane Exposure

Copper balls and tubes CH4/H2 – 40/15 sccm 30 minutes

Copper ball and tube control – 20x

Before cleaning

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

Copper foil

Monolayer, 20x Bilayer, 100x

Future Goals

Confirm graphene growth on Cu tubes and balls

Uniform samples on Ni foil and foam

Sources

http://physicsworld.com/cws/article/news/2010/may/12/few-layer-graphene-keeps-its-cool

http://www.crcnetbase.com/doi/abs/10.1201/b19461-35 “Thermal properties of graphene and few-layer graphene: applications

in electronics” http://ndl.ee.ucr.edu/IET-Review-2015.pdf