Lateral homogeneity of the electronic properties in pristine and ion-irradiated graphene probed by scanning capacitance spectroscopy
1 CNR-IMM, Strada VIII, 5, Zona Industriale, 95121, Catania, Italy
2 Scuola Superiore di Catania, Via San Nullo, 5/I, 95123, Catania, Italy
3 Department of Physics and Astronomy, University of Catania, Via S. Sofia, 95123, Catania, Italy
Nanoscale Research Letters 2011, 6:109 doi:10.1186/1556-276X-6-109Published: 31 January 2011
In this article, a scanning probe method based on nanoscale capacitance measurements was used to investigate the lateral homogeneity of the electron mean free path both in pristine and ion-irradiated graphene. The local variations in the electronic transport properties were explained taking into account the scattering of electrons by charged impurities and point defects (vacancies). Electron mean free path is mainly limited by charged impurities in unirradiated graphene, whereas an important role is played by lattice vacancies after irradiation. The local density of the charged impurities and vacancies were determined for different irradiated ion fluences.