Sorting carbon nanotubes by electronic structure using density differentiation.
The heterogeneity of as-synthesized single-walled carbon nanotubes (SWNTs) precludes their widespread application in electronics, optics and sensing. We report on the sorting of carbon nanotubes by diameter, bandgap and electronic type using structure-discriminating surfactants to engineer subtle differences in their buoyant densities. Using the scalable technique of density-gradient ultracentrifugation, we have isolated narrow distributions of SWNTs in which >97% are within a 0.02-nm-diameter range. Furthermore, using competing mixtures of surfactants, we have produced bulk quantities of SWNTs of predominantly a single electronic type. These materials were used to fabricate thin-film electrical devices of networked SWNTs characterized by either metallic or semiconducting behaviour.
Arnold
Michael S
MS
Department of Materials Science and Engineering, Northwestern University, Evanston, Illinois 60208-3108, USA.
Green
Alexander A
AA
Hulvat
James F
JF
Stupp
Samuel I
SI
Hersam
Mark C
MC
D004581:Electronics / Q000295:instrumentation*; D004867:Equipment Design; D008422:Materials Testing; D008670:Metals / Q000737:chemistry*; D036103:Nanotechnology / Q000295:instrumentation*; D037742:Nanotubes, Carbon / Q000737:chemistry* / Q000648:ultrastructure*; D012666:Semiconductors
D008670:Metals; D037742:Nanotubes, Carbon