Two‐component polymer sorting to obtain high‐purity s‐SWCNTs for all‐carbon photodetectors

Abstract The advancement of carbon‐based electronics is reliant on the development of semiconducting carbon nanotubes with high purity and yield. We developed a new extraction strategy to efficiently sort SWCNTs with superior yields and purity. The approach uses two polymers, poly[N‐(1‐octylnonyl)‐9H‐carbazol‐2,7‐diyl](PCz) and poly(9,9‐n‐dihexyl‐2,7‐fluorene‐alt‐9‐phenyl‐3,6‐carbazole)(PDFP), and two sonication processes to eliminate surface polymer contamination. PCz selectively wraps large‐diameter s‐SWCNTs, with PDFP added as an enhancing molecule to increase sorting efficiency at 4‐fold compared to the efficiency of only PCz alone sorting. The purity of the sorted s‐SWCNTs was confirmed to be above 99 % using absorption and Raman spectra. Field‐effect transistors and photodetectors made from the sorted s‐SWCNTs exhibited excellent semiconductor properties and broad‐spectrum detection, with good long‐term stability. Furthermore, a photodetector using large‐tube diameter s‐SWCNTs achieved broad‐spectrum detection, which the photoresponsivity is 0.35 mA/W and the detectivity is 4.7×10 6 Jones. The s‐SWCNTs/graphene heterojunction photodetector achieved a photoresponsivity of 3 mA/W and a detectivity of 6.3×10 6 Jones. This new strategy provides a promising approach to obtain high‐purity and high‐yield s‐SWCNTs for carbon‐based photodetectors.