Quantifying defects in N-layer graphene via a phenomenological model of Raman spectroscopy

We construct a model to obtain the density of point defects in N-layer graphene by combining Raman spectroscopy and the TRIM (Transport Range of Ions in Matter) simulation package. The model relates the intensity (or area) ratio of graphene's D and G bands to the defect density on each layer due to Ar+ bombardment. Our method is effective for ion fluences ranging from 1011 to ∼1014 Ar+/cm−2 and it should be in principle extendable to any kind of ion and energy.