Transport and performance of a zero-Schottky barrier and doped contacts graphene nanoribbon transistors

Abstract

The transport physics and performance of a top gate graphene nanoribbon (GNR) on an insulator transistor are studied for both the MOSFET like doped source–drain and the zero-Schottky barrier source–drain contacts. A voltage controlled tunnel barrier is the device transport physics. The doped source–drain contact device has a higher gate capacitance, higher transconductance, higher on/off current ratio and higher on-state current. The higher on-state current results in a lower switching delay of 17 fs, and the higher transconductance results in a higher intrinsic cut-off frequency of 27 THz in the doped source–drain contact device. The gate voltage, beyond the source–channel flat band condition, modulates both the tunnel and the thermal barrier in the doped source–drain contact devices and the tunnel barrier only in the Schottky contact devices. This limits the on-state current of Schottky contact devices.