Analytical Current Transport Modeling of Graphene Nanoribbon Tunnel Field-Effect Transistors for Digital Circuit Design

Abstract

A semi-classical and a semi-quantum current transport model for p-i-n n-type armchair graphene nanoribbon tunnel field effect transistor (TFET) are studied analytically. The results are compared with the numerical quantum transport simulation method using an atomistic Schrodinger–Poisson solver within the non-equilibrium Green function (NEGF) formalism. The channel length and width are 20 and 4.9 nm and a-GNR band gap is 0.289 eV. Current ratio ${\rm I_{ON}}/{\rm I_{OFF}}$ at 0.1 V supply voltage is calculated as follows: 122, 16.3 and 116 with a subthreshold slopes 26, 69 and 27.4 mV/decade from semi-classical, semi-quantum and NEGF simulation, respectively. Performance of a-GNR TFET is also studied analytically and numerically considering a-GNR width variation. Voltage transfer characteristics of a-GNR TFET inverter are computed for 0.1 V and 0.2 supply voltages using three current transport models which are in close agreement.