title: Defect scattering in graphene.
abstract: Irradiation of graphene on SiO2 by 500 eV Ne and He ions creates defects that cause intervalley scattering as is evident from a significant Raman D band intensity. The defect scattering gives a conductivity proportional to charge carrier density, with mobility decreasing as the inverse of the ion dose. The mobility decrease is 4 times larger than for a similar concentration of singly charged impurities. The minimum conductivity decreases proportional to the mobility to values lower than 4e(2)/pih, the minimum theoretical value for graphene free of intervalley scattering. Defected graphene shows a diverging resistivity at low temperature, indicating insulating behavior. The results are best explained by ion-induced formation of lattice defects that result in midgap states.
authors: Department of Physics, University of Maryland, College Park, MD 20742 USA.
authors: Jian-Hao
authors: JH
authors: Chen
authors: W G
authors: WG
authors: Cullen
authors: C
authors: C
authors: Jang
authors: M S
authors: MS
authors: Fuhrer
authors: E D
authors: ED
authors: Williams