Chemically Functionalized Semiconducting Carbon Nanotubes: Limits for High Conductance Performance

TL;DR

This study uses first-principles calculations to show that covalent functionalization with carbene groups significantly reduces the conductance of semiconducting carbon nanotubes, challenging the development of high-performance functionalized nanotubes.

Contribution

It provides the first detailed analysis of how carbene functional groups impact the electronic transport in semiconducting carbon nanotubes, highlighting limitations for high conductance applications.

Findings

Semiconducting CNT conductance is severely damaged by carbene functionalization.

Conductance decreases with increasing tube diameter and coverage.

Covalent functionalization routes that preserve conductance are difficult to achieve.

Abstract

We present a first-principles study of the electronic transport properties of micrometer long semiconducting CNTs randomly covered with carbene functional groups. Whereas prior studies suggested that metallic tubes are hardly affected by such addends, we show here that the conductance of semiconducting tubes with standard diameter is on the contrary severely damaged. The configurational averaged conductance as a function of tube diameter and with a coverage of up to one hundred functional groups is extracted. Our results indicate that the search for a conductance-preserving covalent functionalization route remains a challenging issue.