▎ 摘　　要

Few-layer graphene has been prepared on 300 nm-thick Ni films by C-2-C-6 cluster ion implantation at 20 key/cluster. Raman spectroscopy reveals significant influence of the number of atoms in the cluster, the implantation dose, and thermal treatment on the structure of the graphene layers. In particular, the graphene samples exhibit a sharp G peak at 1584 cm(-1) and 2D peaks at 2711-2717 cm(-1). The I-G/I-2D ratios higher than 1.70 and I-G/I-D ratio as high as 1.95 confirm that graphene sheets with low density of defects have been synthesized with much improved quality by ion implantation with larger clusters of C-4-C-6. (C) 2013 Published by Elsevier B.V.