Realization of a high mobility dual-gated graphene field-effect transistor with $Al2O3$ dielectric

We fabricate and characterize dual-gated graphene field-effect transistors using $Al2O3$ as top-gate dielectric. We use a thin Al film as a nucleation layer to enable the atomic layer deposition of $Al2O3$⁠. Our devices show mobility values of over $8000cm2/Vs$ at room temperature, a finding which indicates that the top-gate stack does not significantly increase the carrier scattering and consequently degrade the device characteristics. We propose a device model to fit the experimental data using a single mobility value.