Effects of the Molecular Weight of PCz on Selective Extraction of Large-Diameter Semiconducting Single-Walled Carbon Nanotubes

Abstract

Due to the difficulty in the selective synthesis of semiconductor (s-) and metal (m-) single-walled carbon nanotubes (SWCNTs), we still need to explore the selective extraction technology of s-SWCNTs. Using Poly[9-(1-octylonoyl)-9H-carbazole-2,7-diyl] (PCz) extraction of s-SWCNTs has attracted extensive attention in recent years, because it can selective extraction of large-diameter s-SWCNTs with high purity. However, influence of the molecular weight of this polymer on the s-SWCNTs selective extraction properties remains unclear. In this study, we used PCz with different average molecular weights to study the ability of selective extraction s-SWCNTs from pristine arc discharge carbon nanotubes. Spectra studies indicate that compared to the PCz with lower molecular weight, the PCz with higher molecular weight has better selective extraction ability, and can help to obtain s-SWCNTs with higher purity (>99%) and high yield. FETs devices have been prepared by s-SWCNTs obtained via PCz with higher molecular weight exhibit higher on/off ratio, lower off current and lower subthreshold swing. This work offers a reference of the design and synthesis of PCz polymer that performs sufficient selective ability in extracting s-SWCNTs with promising applications.