Letter abstract


Nature Nanotechnology 3, 654 - 659 (2008)
Published online: 21 September 2008 | doi:10.1038/nnano.2008.268

Subject term: Electronic properties and devices

Current saturation in zero-bandgap, top-gated graphene field-effect transistors

Inanc Meric1, Melinda Y. Han2, Andrea F. Young3, Barbaros Ozyilmaz3,4, Philip Kim3 & Kenneth L. Shepard1


The novel electronic properties of graphene1, 2, 3, 4, including a linear energy dispersion relation and purely two-dimensional structure, have led to intense research into possible applications of this material in nanoscale devices. Here we report the first observation of saturating transistor characteristics in a graphene field-effect transistor. The saturation velocity depends on the charge-carrier concentration and we attribute this to scattering by interfacial phonons in the SiO2 layer supporting the graphene channels5, 6. Unusual features in the current–voltage characteristic are explained by a field-effect model and diffusive carrier transport in the presence of a singular point in the density of states. The electrostatic modulation of the channel through an efficiently coupled top gate yields transconductances as high as 150 µS µm−1 despite low on–off current ratios. These results demonstrate the feasibility of two-dimensional graphene devices for analogue and radio-frequency circuit applications without the need for bandgap engineering.

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  1. Department of Electrical Engineering, Columbia University, New York 10027, USA
  2. Department of Applied Physics and Applied Mathematics, Columbia University, New York 10027, USA
  3. Department of Physics, Columbia University, New York 10027, USA
  4. Present Address: Department of Physics, NUS 2 Science Drive 3, 117542 Singapore

Correspondence to: Kenneth L. Shepard1 e-mail: shepard@ee.columbia.edu



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