Preferential Growth of Single-Walled Carbon Nanotubes with Metallic Conductivity

Avetik R. Harutyunyan, Honda Res Inst
Gugang Chen, Honda Res Inst
Tereza M. Paronyan, University of Louisville
Elena M. Pigos, Honda Res Inst
Oleg A. Kuznetsov, Honda Res Inst
Kapila Hewaparakrama, University of Louisville
Seung M. Kim, Purdue University - Main Campus
Dmitri Zakharov, Purdue University - Main Campus
E A. Stach, Birck Nanotechnology Center and School of Materials Engineering, Purdue University
Gamini U. Sumanasekera, University of Louisville

Abstract

Single-walled carbon nanotubes can be classified as either metallic or semiconducting, depending on their conductivity, which is determined by their chirality. Existing synthesis methods cannot controllably grow nanotubes with a specific type of conductivity. By varying the noble gas ambient during thermal annealing of the catalyst, and in combination with oxidative and reductive species, we altered the fraction of tubes with metallic conductivity from one-third of the population to a maximum of 91%. In situ transmission electron microscopy studies reveal that this variation leads to differences in both morphology and coarsening behavior of the nanoparticles that we used to nucleate nanotubes. These catalyst rearrangements demonstrate that there are correlations between catalyst morphology and resulting nanotube electronic structure and indicate that chiral-selective growth may be possible.

Discipline(s)

Engineering | Nanoscience and Nanotechnology