Heavily p-type doped chemical vapor deposition graphene field-effect transistor with current saturation

Current saturation in graphene field-effect transistor (GFET) is of significant importance to improve the maximum oscillation frequency (f(max)). We investigated the direct current (dc) and radio frequency (rf) characteristics of a heavily p-type doped GFET based on chemical vapor deposition grown material. The drain current saturation is found in our device. It cannot be explained by the pinch-off effect associated with ambipolar transport, but can be attributed to nonlinear channel conductance and velocity saturation in unipolar channel. This study promotes understanding the behaviors of heavily doped GFETs and their radio frequency applications. (C) 2013 AIP Publishing LLC.