We present a detailed study of the high-current transport properties of graphene devices patterned in a four-point configuration. The current tends to saturate as the voltage across graphene is increased but never reaches the complete saturation as in metallic nanotubes. The current in the saturation regime can be modulated by sweeping the backgate voltage. Measurements are compared to a model based on the Boltzmann equation, which includes electron scattering processes due to charged and neutral impurities, and graphene optical-phonons. The current saturation arises from the balance between elastic and optical-phonon scattering. Finally, we identify the signature of interband Klein tunneling
EventList powered by schlu.net