Controlling Electron-Phonon Interactions in Graphene at Ultrahigh Carrier Densities

We report on the temperature dependent electron transport in graphene at different carrier densities $n$. Employing an electrolytic gate, we demonstrate that $n$ can be adjusted up to $4\ifmmode\times\else\texttimes\fi{}{10}^{14}\text{ }\text{ }{\mathrm{cm}}^{\ensuremath{-}2}$ for both electrons and holes. The measured sample resistivity $\ensuremath{\rho}$ increases linearly with temperature $T$ in the high temperature limit, indicating that a quasiclassical phonon distribution is responsible for the electron scattering. As $T$ decreases, the resistivity decreases more rapidly following $\ensuremath{\rho}(T)\ensuremath{\sim}{T}^{4}$. This low temperature behavior can be described by a Bloch-Gr\"uneisen model…