Nanoscale modification of graphene transport properties by ion irradiation

Single layers of graphene (SLG) mechanically exfoliated from highly oriented pyrolytic graphite and deposited on SiCVSi were irradiated with C + ions at different fluences (from 10 13 to 10 14cm -2), in order to modify the transport properties in controlled way. Using a method based on scanning probe microscopy, local measurements of the electron mean free path (I) have been carried out both on pristine and ion irradiated SLG. A lateral inhomogeneity of l was found in both cases, with an increasing spread in the distribution of l for larger fluences. Before irradiation, the spread was explained by the inhomogeneous distribution of charged impurities on SLG surface and/or at the interface with SiO 2. After irradiation, lattice vacancies cause a local reduction of l in the damaged regions.