Using Superlattice Structure in the Source of GNRFET to Improve Its Switching Performance

Our aim is to improve the switching performance of the graphene nanoribbon field-effect transistors (GNRFETs), exploiting the concept of energy filtering. Within the proposed scheme, a superlattice (SL) structure is used in the source of the transistor for filtering high-energy electron tail by engineering the density of states (DOS). According to simulation results, this can significantly decrease the OFF-current and the subthreshold swing (SS). A comparison of the proposed device with a conventional GNRFET and a graphene nanoribbon (GNR) tunneling field-effect transistor (GNRTFET) demonstrates a significant improvement. Therefore, a typical SL-GNRFET can reduce the average and the minimum of the SS to 44.6 and 12.5 mV/dec, respectively, at room temperature. Moreover, in order to optimize the proposed structure, the effects of the SL geometrical parameters on the transistor characteristics are numerically investigated.