Year: 2010
Type: article
Abstract: We present a study of transport in graphene devices on polar insulating substrates by solving the Boltzmann transport equation in the presence of graphene phonon, surface polar phonon, and Coulomb charged impurity scattering. The value of the saturated velocity shows very weak dependence on the carrier density, the nature of the insulating substrate, and the low-field mobility, varied by the charged impurity concentration. The saturated velocity of $4\ifmmode\times\else\texttimes\fi{}{10}^{7}--8\ifmmode\times\else\texttimes\fi{}{10}^{7}\text{ }\text{cm}/\text{s}$ calculated at room temperature is significantly larger than reported experimental values. The discrepancy is due to the self-heating effect which lowers substantially the value of the saturated velocity. We predict that by reducing the insulator oxide thickness, which limits the thermal conductance, the saturated currents can be significantly enhanced. We also calculate the surface polar phonon contribution to the low-field mobility as a function of carrier density, temperature, and distance from the substrate.
Source: Physical Review B
Authors: Vasili Perebeinos, Phaedon Avouris
Institution: IBM Research - Thomas J. Watson Research Center
Language: English
Subfield: Materials Chemistry
Field: Materials Science
Domain: Physical Sciences
Open Access status: green
Funder: University of Notre Dame
OpenAlex ID: W2090655081