Abstract
Heated up in H2 and N2 respectively at the heating-up stage, the copper foils were used as the substrates to fabricate graphene by low pressure chemical vapor deposition. The fabricated graphene presented different characteristics. Heated up in H2, on the substrate appeared polycrystalline films with small domains of poor quality; while in N2, the size of the graphene domain was up to 500 μm with good quality. The results indicated that the heating-up atmosphere caused the differences in graphene morphology by changing the surface microstructure of the substrate. In N2, the copper surface tended to become smoother, leading to difficult nucleation; while in H2, plenty of terraced steps appeared on the surface of the substrate, providing much more favorable sites for active carbon atoms to cluster and nucleate.