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 pi-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 pi-pi 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 (mu(e)) of 7.43 cm(2) V-1 s(-1), while PNBDO-FDTE90 and PNBDO-FDTE80 also showed impressively high mu(e) values of 7.25 and 6.00 cm(2) V-1 s(-1), respectively. However, PNBDO-FDTEm (m = 70, 60, and 0) afforded a mu(e) as low as 0.182 cm(2) V-1 s(-1). We attributed this to the transition of the carrier transport mode caused by the increase in the number of p-nonconjugated nodes.