Effect of stone-wales defects and edge roughness on the switching and frequency performance of graphene nanoribbon-FET

Abstract

The novel electronic properties of graphene nanoribbons (GNRs) including purely two-dimensional structure along with its tunable bandgap have led to intense research into possible applications of this material in nanoscale devices. However, as yet, dimensions of its possibilities in practical device levels have remained inconsistent. In this paper we propose a model for GNR-FET that is made from only Armchair GNRs. Our complete NEGF-based simulation reveals its potential for fast digital electronics with On/Off ratio up to 10 3 , transconductance of 8.5 10 3 nS/nm which lead to a analog operational frequency up to 3.3THz. The effects of Stone-Wales defects and Edge Roughness in GNRs have been analysed here that shows switching and frequency performance degradation of such GNR-FETs.

Review on graphene nanoribbon devices for logic applications

“…As discussed in [117], these defects alter the electronic transport properties of GNRs and may result in bandgap enhancement if the defect is located near the source region in AGNRFETs, as well as drain current reduction. This is consistent with [99], where a TB P Z orbital model with 3 nearest neighbors is used to calculate the electronic transport properties of an AGNR-FET by means of NEGF coupled with Poisson's Equation, showing that the drain current is significantly reduced for any bias voltage and the I on =I off ratio reduces 2 orders of magnitude. These results are consistent to the calculations presented in [114].…”

“…Furthermore, narrower GNRs are more sensitive to this defect since the simulations show that both mobility and bandgap are more variable. Then, the model presented in [99] takes into account these defects and show that the I on =I off ratio goes from 1000 to 16, in addition to 33% decrease in operational frequency, when considering edge defects.…”