Effect of cooling condition on chemical vapor deposition synthesis of graphene on copper catalyst.
Here, we show that chemical vapor deposition growth of graphene on copper foil is strongly affected by the cooling conditions. Variation of cooling conditions such as cooling rate and hydrocarbon concentration in the cooling step has yielded graphene islands with different sizes, density of nuclei, and growth rates. The nucleation site density on Cu substrate is greatly reduced when the fast cooling condition was applied, while continuing methane flow during the cooling step also influences the nucleation and growth rate. Raman spectra indicate that the graphene synthesized under fast cooling condition and methane flow on cool-down exhibit superior quality of graphene. Further studies suggest that careful control of the cooling rate and CH4 gas flow on the cooling step yield a high quality of graphene.
School of Advanced Materials Science and Engineering, Sungkyunkwan University , Suwon 440-746, Republic of Korea.
Dong Soo
DS
Choi
Keun Soo
KS
Kim
Hyeongkeun
H
Kim
Yena
Y
Kim
TaeYoung
T
Kim
Se-hyun
SH
Rhy
Cheol-Min
CM
Yang
Dae Ho
DH
Yoon
Woo Seok
WS
Yang
CVD; cooling rate; grain; graphene; growth