Reversible Defect in Graphene Investigated by Tip-Enhanced Raman Spectroscopy

In this paper, a single defect in graphene was created by an Au nanoparticle attached to atomic force tip working in tapping mode. Then it was investigated by tip-enhanced Raman spectroscopy (TERS). The TERS tip interacted with the graphene are able to induce an atomic deformation of carbonic structure which then can be recovered after retracting the tip. The reversible defect was confirmed by the iterative observation of D-band Raman signal of graphene as the tip force on and off. Further more, the Au particles as a nano-antenna can enhance the weak D-band signal from the single graphene defect significantly. These finds will give us better understanding of the origination of graphene defects and the interaction between nanoparticles and graphene.