Supramolecular interactions of poly[(9,9-dioctylfluorenyl-2,7-diyl)-co- thiophene] with single-walled carbon nanotubes

Efficient selective extraction of semiconducting single-walled carbon nanotubes (s-SWCNTs) from as-synthesized SWCNTs is essential for their electronic and photovoltaic applications. In this study, we used a relatively simple copolymer backbone structure of poly[(9,9-dioctylfluorenyl-2,7-diyl)-co-thiophene] (PFT) for the selective extraction of s-SWCNTs from HiPCO SWCNTs. The absorption and Raman spectroscopies indicated that the PFT-sorted s-SWCNTs had high purity which was far beyond the sensitivity of the spectrometers. Photoluminescence excitation spectroscopy showed that PFT mainly extracted the chiralities of (n,m)=(9,5), (8,6), (7,5), and (10,5) s-SWCNTs with the ratios of about 53.1%, 24.8%, 11.5%, and 10.5%, respectively. Both steady-state and transient optical spectroscopies suggested that there was a strong interaction between PFT and s-SWCNTs. Molecular dynamics simulation results agreed well with the experimental data. Additionally, the photoinduced energy transfer behavior of the PFT-wrapped s-SWCNT resultant hybrid was assessed. This work indicated that the prepared PFT-wrapped s-SWCNT hybrid material was attractive for organic photovoltaic devices.