Contact Dependence of Carrier Injection in Carbon Nanotubes: An Ab Initio Study

TL;DR

This study uses ab initio calculations and transport modeling to understand how different metal contacts affect carrier injection in carbon nanotubes, highlighting the importance of hybridization and contact length.

Contribution

It provides a microscopic understanding of metal-nanotube contact quality, comparing Ti and Pd, and proposes criteria for optimal contact design.

Findings

Pd forms better contacts than Ti due to hybridization differences

Optimal contacts require weak hybridization and large contact length

The study combines density functional theory with Landauer transport calculations

Abstract

We combine ab initio density functional theory with transport calculations to provide a microscopic basis for distinguishing between good and poor metal contacts to nanotubes. Comparing Ti and Pd as examples of different contact metals, we trace back the observed superiority of Pd to the nature of the metal-nanotube hybridization. Based on large scale Landauer transport calculations, we suggest that the `optimum' metal-nanotube contact combines a weak hybridization with a large contact length between the metal and the nanotube.