Modifying electronic transport properties of graphene by electron beam irradiation

We demonstrate that electron beam irradiation with precise dosage control under clean vacuum conditions can induce bond disorder and inter-valley scattering but not necessarily lattice damage in high quality single-layer graphene, as evidenced by the changes of temperature-dependent transport properties, quantum Hall effects, and large negative magnetoresistance effects observed at cryogenic temperatures. The bond disorder significantly modified the Raman scattering and electronic transport properties of graphene, which is consistent with that observed in hydrogenated graphene. In situ transport measurements at different sample treatment stages revealed an interesting activation process of graphene through electron beam irradiation. The activated graphene samples are very sensitive to oxygen and water vapors. (C) 2011 American Institute of Physics. [doi:10.1063/1.3615294]