A simple drain current model for Schottky-barrier carbon nanotube field effect transistors

TL;DR

This paper introduces a computational model for simulating Schottky-barrier carbon nanotube FETs, capturing key physical effects and operational regimes with efficiency and accuracy comparable to advanced NEGF methods.

Contribution

A new simplified model for CNT-FETs that accurately incorporates Schottky barrier physics and operational regimes, offering computational efficiency over existing methods.

Findings

Model accurately predicts I-V characteristics.

Captures thermionic and tunneling currents.

Agrees with NEGF-based results.

Abstract

We report on a new computational model to efficiently simulate carbon nanotubebased field effect transistors (CNT-FET). In the model, a central region is formed by a semiconducting nanotube that acts as the conducting channel, surrounded by a thin oxide layer and a metal gate electrode. At both ends of the semiconducting channel, two semi-infinite metallic reservoirs act as source and drain contacts. The current-voltage characteristics are computed using the Landauer formalism, including the effect of the Schottky barrier physics. The main operational regimes of the CNT-FET are described, including thermionic and tunnel current components, capturing ambipolar conduction, multichannel ballistic transport and electrostatics dominated by the nanotube capacitance. The calculations are successfully compared to results given by more sophisticated methods based on non-equilibrium Green's function formalism (NEGF).