Sorting Semiconducting Single-Walled Carbon Nanotubes by Water-Soluble Polyfluorene Assisted Electrophoresis and Its Application in Field-effect Transistors

We report a considerably promising method based on agarose gel electrophoresis (AGE) to separate single-walled carbon nanotubes by adding a water-soluble polyfluorene (w-PFO) as surfactant into the agarose gel. In this effective method, the AGE/w-PFO gel network will trap more semiconducting single-walled carbon nanotubes (SWNTs) with the assistance of w-PFO, for the strong interaction between w-PFO and semiconducting species. The optical absorbance, photoluminescence emission and resonant Raman scattering characterization were used to verify the separation effect. The purity of separated semiconducting species is as high as (98 +/- 1)%. The demonstrated field effect transistors give the on/off ratio and mobility about 27000 and 10.2 cm(2)center dot V-1 center dot s(-1), respectively.