Ballisticity of nanotube FETs: Role of phonon energy and gate bias

TL;DR

This paper explores how electron-phonon interactions and gate bias affect the current in nanotube FETs, revealing that elastic scattering and phonon energy significantly influence device performance.

Contribution

It provides new insights into the impact of phonon energy and gate bias on nanotube FETs, highlighting the importance of elastic scattering mechanisms.

Findings

Elastic scattering is most harmful above a certain gate voltage threshold.

Lower phonon energy causes greater drive current degradation.

Radial breathing mode phonons significantly reduce drive current.

Abstract

We investigate the role of electron-phonon scattering and gate bias in degrading the drive current of nanotube MOSFETs. Our central results are: (i) Optical phonon scattering significantly decreases the drive current only when gate voltage is higher than a well-defined threshold. It means that elastic scattering mechanisms are most detrimental to nanotube MOSFETs. (ii) For comparable mean free paths, a lower phonon energy leads to a larger degradation of drive current. Thus for semiconducting nanowire FETs, the drive current will be more sensitive than carbon nanotube FETs because of the smaller phonon energies in semiconductors. (iii) Radial breathing mode phonons cause an appreciable reduction in drive current.