Preferential growth of single-walled carbon nanotubes with metallic conductivity.
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.
Harutyunyan
Avetik R
AR
Honda Research Institute USA, 1381 Kinnear Road, Columbus, OH 43212, USA. aharutyunyan@honda-ri.com
Chen
Gugang
G
Paronyan
Tereza M
TM
Pigos
Elena M
EM
Kuznetsov
Oleg A
OA
Hewaparakrama
Kapila
K
Kim
Seung Min
SM
Zakharov
Dmitri
D
Stach
Eric A
EA
Sumanasekera
Gamini U
GU