High-Electron Mobility Tetrafluoroethylene-Containing Semiconducting Polymers

Herein, we report a series of tetrafluoroethylene (TFE)-containing semiconducting polymers PNBDO-FDTEm (m = 90, 80, 70, 60, and 0), in which the TFE segments were first introduced into polymeric main chains as flexible π-nonconjugated nodes, and its fully conjugated analogue PNBDO-FDTE100. Our results indicate that the TFE segment is quite compatible with the NBDO-alt-FDTE conjugated matrix system. The HOMO/LUMO energy levels (approximately −6.0/–4.0 eV) and optical band gaps (1.28 eV) remain almost the same in the polymers with the TFE content varying from 0% to 40%. The polymers PNBDO-FDTEm (m = 90, 80, 70, and 60) have similar highly ordered molecular packing with close π–π stacking in a thin film as PNBDO-FDTE100 does, implying that the TFE segments exert no clear negative influences on the molecular packing of these polymers either. PNBDO-FDTE100 exhibited a much high electron mobility (μ_e) of 7.43 cm² V^–1 s^–1, while PNBDO-FDTE90 and PNBDO-FDTE80 also showed impressively high μ_e values of 7.25 and 6.00 cm² V^–1 s^–1, respectively. However, PNBDO-FDTEm (m = 70, 60, and 0) afforded a μ_e as low as 0.182 cm² V^–1 s^–1. We attributed this to the transition of the carrier transport mode caused by the increase in the number of π-nonconjugated nodes.