Senior Honors Thesis

Tuesday, May 31, 2016, Wilder 104, 3:00 PM

Muhammad H. Kiani, Department of Physics and Astronomy Dartmouth College

Title: Fabrication and Characterization of Graphene Devices

Abstract: Graphene is a one-atom-thick 2D crystal of carbon atoms that form a hexagonal lattice. As a consequence of this structure, graphene has a linear energy dispersion relation about the Dirac point where the valence and conduction bands meet. The chemical potential in graphene can be changed using a back-gate allowing us to not only control the density of states, but also to tune the system between electron-mediated metallic conduction, insulating and hole-mediated metallic conduction regimes. The first part of the project involves fabricating graphene devices with low-resistance electrical contacts (ohmic) without affecting the underlying properties of graphene and exploring the effects of various processing parameters (annealing, plasma treatment, etc.). The second part involves electrically characterizing the prepared graphene samples: making sure that we can control the density of states as desired. Since the density of states determines the resistivity, characterizing samples involves making four-point resistivity measurements as a function of the back-gate voltage at various temperatures. This project will enable us in the future to explore hyperfine interactions in graphene while controlling its electronic density of states.