Large physisorption strain and edge modification of Pd on monolayer graphene.

Using Raman spectroscopic studies, we firstly report that Pd film deposition can induce a tensile strain at the interface between Pd and n-layer graphenes, which results in the splitting of the G peak and a red Raman shift of the 2D peak in monolayer graphene, and red Raman shifts of G and 2D peaks for other n-layer graphenes. In particular, this kind of tensile strain can be used as an effective way for edge modification or strain engineering in monolayer graphene.