▎ 摘　　要

Different metal films (Co, Ni, Au, and Ag) were deposited on graphene and the interactions between these metals and graphene were studied by Raman spectroscopy. The Raman peaks were shifted after the deposition of metal films. The electron doping of graphene with cobalt contacts and the hole doping with the nickel contacts are the main reasons for Raman peak shift. However, for gold contacts and silver contacts with graphene, strain effect dominates Raman peak shift instead of charge transfer. (C) 2011 American Institute of Physics. [doi:10.1063/1.3536670]