▎ 摘　　要

The copper foils covered by oxide layers with different thicknesses, i.e. the naturally-oxidized substrate and the intentionally-oxidized substrate were prepared to fabricate graphene by low pressure chemical vapor deposition. To prevent the oxide layer being reduced in the heating stage, N-2 was introduced into the growth chamber. The results indicated that although the graphene nucleation density on both substrates was reduced effectively, that on the intentionally-oxidized substrate was lower. Meanwhile, the graphene domains on the intentionally-oxidized substrate were monolayer with better crystal quality as well as larger size while that on the naturally-oxidized substrate possessed poor quality caused by the coexistence of monolayer and few-layer graphene. Based on the analysis of the morphological changes of the substrate surface caused by the oxide layer in different growth stages, the mechanism of the oxide layer affecting graphene nucleation and growth was investigated. And an easier and effective way to fabricate large-sized graphene domains with good quality was also proposed.