Electron transport in semiconducting carbon nanotubes with hetero-metallic contacts

TL;DR

This study investigates how hetero-metallic contacts influence electron transport in semiconducting carbon nanotubes, revealing the roles of charge transfer, band alignment, and interface effects in device performance.

Contribution

It provides an atomistic, self-consistent analysis of contact-induced doping and interface effects on electron transport in nanotube devices, highlighting the decoupling of interface and bulk influences.

Findings

Charge transfer causes simultaneous electron and hole doping.

Band lineup is governed by work function differences.

Interface effects modulate local band structure and transmission.

Abstract

We present an atomistic self-consistent study of the electronic and transport properties of semiconducting carbon nanotube in contact with metal electrodes of different work functions, which shows simultaneous electron and hole doping inside the nanotube junction through contact-induced charge transfer. We find that the band lineup in the nanotube bulk region is determined by the effective work function difference between the nanotube channel and source/drain electrodes, while electron transmission through the SWNT junction is affected by the local band structure modulation at the two metal-nanotube interfaces, leading to an effective decoupling of interface and bulk effects in electron transport through nanotube junction devices.