3:00 pm in the Conference Room of the Marcus Nanotechnology Building
Georgia Tech College of Science, MRSEC, & School of Physics Colloquium
Walter de Heer
School of Physics
Georgia Institute of Technology
"Epitaxial graphene: designing a new electronic material"
Since 2001 researchers at Georgia Tech and their collaborators have investigated the extraordinary transport properties of epitaxial graphene and demonstrated its promise as a new electronic material. Epitaxial graphene is grown on various crystal faces of silicon carbide and it can be patterned using standard microelectronics methods. Graphene grown on the carbon-terminated face is multilayered and it is particularly interesting. It consists of up to 100 graphene sheets. yet its properties are similar to those of monolayer graphene. Multilayered epitaxial graphene has been extensively studied using a variety of probes. Like ideal graphene, its the band structure is defined by a “Dirac cone” and it exhibits the half integer quantum Hall effect. Weak anti-localization and electronic quantum confinement in patterned ribbons has been demonstrated. These properties confirm that the chiral nature of the carriers in the material, which distinguishes it from graphite. Record-breaking room temperature mobilities have been measured and Landau levels are well-resolved even at room temperatures in weak magnetic fields. Furthermore, semi-metallic epitaxial graphene has been converted in-situ to semiconducting graphene oxide. All these properties indicate that epitaxial graphene not only is a fascinating material for fundamental physics, but may become a new platform for ultrahigh speed electronics.
