1.Introduction to Graphene
●Graphene is an one-atom-thick carbon material, with carbon atoms packed densely in a hexagonal honeycomb lattice.
●Graphene is a basic building block for graphitic materials of all other dimensionalities. It can be wrapped up into 0D fullerenes, rolled into 1D nanotubes or stacked into 3D graphite.
2.Characteristics of Graphene
●Room-Temperature quantum Hall effect.
●A new "half-integer" quantum Hall effect.
●Electrons have no rest mass and travel at about 106 m/s. (light speed: 3 x 108 m/s).
●Intrinsic Carrier Mobility of ~200,000 cm2/V-s.
●Ballistic transport on submicron to micron distances.
●g.High mechanical strength and elasticity.
3.Synthesis of Graphene
a.Micromechanical exfoliation (Scotch tape method)
●Small flakes of sample, useful for fundamental study.
b.Epitaxial graphene (EG) on SiC
●Ultra-high vacuum and high process temperature (> 1000℃).
●Strong cohesive strength of EG/SiC interface and extreme chemical stability of SiC make it difficult to transfer EG to another substrate .
●May be modified by solid-phase extraction method
c.Chemical Vapor Deposition (CVD)
●Synthesis of graphene on transition metals (Surface segregation method)
●Substrate -free CVD, Plasma-enhanced CVD, Aerosol pyrolysis and solvothermal synthesis
●Large-area graphene films
●Transfer to other substrates easily achieved by etching off the transition metals by acid solutions
●Made from graphite or derivatives of graphite (graphite oxide)
●Scalable, versatile, and suited to chemical functionalization
●Structure damage by strong oxidation agent-restoration required during or after reduction process