It remains an elusive goal to achieve high performance single-walled carbonnanotube (SWNTs) field effect transistors (FETs) comprised of only singlechirality SWNTs. Many separation mechanisms have been devised and variousdegrees of separation demonstrated, yet it is still difficult to reach the goalof total fractionation of a given nanotube mixture into its single chiralitycomponents. Chromatography has been reported to separate small SWNTs (diameterless than 0.9nm) according to their diameter, chirality and length. Theseparation efficiency decreased with increasing tube diameter by using ssDNAsequence d(GT)n (n=10-45). Here we report our result on the separation ofsingle chirality (10,5) SWNTs (diameter = 1.03nm) from HiPco tubes with ionexchange chromatography. The separation efficiency was improved by using a newDNA sequence (TTTA)3T which can recognize SWNTs with the specific chirality(10,5). The chirality of the separated tubes was examined by opticalabsorption, Raman, photoluminescence excitation/emission and electricaltransport measurement. All spectroscopic methods gave single peak of (10,5)tubes. The purity was 99% according to the electrical measurement. The FETscomprised of separated SWNTs in parallel gave Ion/Ioff ratio up to 106 owningto the single chirality enriched (10,5) tubes. This is the first time that SWNTFETs with single chirality SWNTs were achieved. The chromatography method hasthe potential to separate even larger diameter semiconducting SWNTs from otherstarting material for further improving the performance of the SWNT FETs.
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