Giant Intrinsic Carrier Mobilities in Graphene and Its Bilayer

Abstract

We have studied temperature dependences of electron transport in graphene and its bilayer and found extremely low electron-phonon scattering rates that set the fundamental limit on possible charge carrier mobilities at room temperature. Our measurements show that mobilities higher than $200000{\mathrm{cm}}^2/\mathrm{V}\mathrm{s}$ are achievable, if extrinsic disorder is eliminated. A sharp (thresholdlike) increase in resistivity observed above $\sim 200\mathrm{K}$ is unexpected but can qualitatively be understood within a model of a rippled graphene sheet in which scattering occurs on intraripple flexural phonons.