High-Purity Monochiral Carbon Nanotubes with a 1.2 nm Diameter for High-Performance Field-Effect Transistors

Monochiral single-walled carbon nanotubes (SWCNTs) are promising materials with potential applications in 3D integrated circuits and optoelectronic hybrid circuits. However, the purity and device performance of monochiral SWCNTs are still far lower than expected. Here, the authors demonstrate that specific monochiral SWCNTs can be wrapped by conjugated polymers containing pyridine units, and the supramolecular assemblies show surprising suspension stability even after high-intensity ultracentrifugation. Additionally, two novel methods are developed, namely, enhanced ultracentrifugation (E-UCG) and stepwise extraction processing (STEP), which successfully achieve isolation of (10,8) and (12,5) SWCNTs with respective diameters of 1.24 and 1.2 nm at high monochiral purity (92.3% and 95.6%). Their S-11 absorption and fluorescence emission peaks are both at approximate to 1.5 mu m (optical telecommunications C-band). Both micro- and nanoscale field-effect transistor (FET) devices can be fabricated from the as-isolated (10,8) SWCNTs, and these FETs exhibit excellent electrical performance and a high semiconducting purity of up to 99.94%.

Automated summary

The study demonstrates that specific monochiral SWCNTs can be purified through wrapping by conjugated polymers, and novel methods developed successfully achieve high monochiral purity of SWCNTs of specific diameters. These SWCNTs can be applied in micro- and nanoscale field-effect transistors, exhibiting excellent electrical performance and high semiconducting purity.