Semiconductor to metal transition in SWNTs caused by interaction with gold and platinum nanoparticles

TL;DR

This study demonstrates that gold and platinum nanoparticles induce a semiconductor to metal transition in single-walled carbon nanotubes through charge transfer, confirmed by Raman spectroscopy and ab-initio calculations.

Contribution

It provides new insights into how metal nanoparticle interactions can modify the electronic properties of SWNTs, highlighting a controllable transition mechanism.

Findings

Increased metallic character in SWNTs after nanoparticle attachment

Raman spectra show changes consistent with semiconductor-metal transition

Ab-initio calculations confirm charge transfer causes the transition

Abstract

Single-walled carbon nanotubes (SWNTs) have been coated with gold and platinum nanoparticles either by microwave treatment or by the click reaction and the Raman spectra of these SWNT-metal nanoparticle composites have been investigated. Analysis of the G bands in the Raman spectra shows an increase in the proportion of metallic SWNTs on attachment with metal nanoparticles. This conclusion is also supported by the changes observed in the RBM bands. Ab-initio calculations reveal that semiconductor-metal transition occurs in SWNTs due to Columbic charge transfer between the metal nanoparticles and the semiconducting SWNTs.