Band-to-band tunneling in a carbon nanotube metal-oxide-semiconductor field-effect transistor is dominated by phonon assisted tunneling

TL;DR

This study uses advanced simulations to show that phonon-assisted processes dominate band-to-band tunneling in carbon nanotube MOSFETs, impacting their electrical behavior and potential for low-power electronics.

Contribution

The paper provides the first detailed simulation evidence that phonon-assisted tunneling dominates in CNT-MOSFETs, highlighting the importance of inelastic transport mechanisms.

Findings

BTBT in CNT-MOSFETs is dominated by optical phonon assisted inelastic transport

Two-phonon scattering becomes significant under large bias conditions

Simulation results align with experimental data

Abstract

Band-to-band tunneling (BTBT) devices have recently gained a lot of interest due to their potential for reducing power dissipation in integrated circuits. We have performed extensive simulations for the BTBT operation of carbon nanotube metal-oxide-semiconductor field-effect transistors (CNT-MOSFETs) using the non-equilibrium Green's functions formalism for both ballistic and dissipative quantum transport. In comparison with recently reported experimental data (Y. Lu et al, J. Am. Chem. Soc., v. 128, p. 3518-3519, 2006), we have obtained strong evidence that BTBT in CNT-MOSFETs is dominated by optical phonon assisted inelastic transport, which can have important implications on the transistor characteristics. It is shown that under large biasing conditions two-phonon scattering may also become important.