Methanol as a carbon source in chemical vapor deposition (CVD) graphene has an advantage
over methane and hydrogen in that we can avoid optimizing an etching reagent condition.
Since methanol itself can easily decompose into hydrocarbon and water (an etching
reagent) at high temperatures [1], the pressure and the temperature of methanol are the only
parameters we have to handle. In this study, synthetic conditions for highly crystalline and
large area graphene have been optimized by adjusting pressure and temperature; the effect
of each parameter was analyzed systematically by Raman, scanning electron microscope,
transmission electron microscope, atomic force microscope, four-point-probe measurement,
and UV-Vis. Defect density of graphene, represented by D/G ratio in Raman, decreased with
increasing temperature and decreasing pressure; it negatively affected electrical conductivity.
From our process and various analyses, methanol CVD growth for graphene has been
found to be a safe, cheap, easy, and simple method to produce high quality, large area, and
continuous graphene films.