Abstract: A pulsed driven display comprising an organic light-emitting device, said device comprising an organic layer comprising a semiconductive polymer, said polymer comprising a fluorene or triarylamine repeat unit, the fluorene or triarylamine repeat unit having a group R pendent from the polymer backbone, wherein R has general formula I: where Ar1 represents phenyl or a group comprising napthyl; Ar2 represents phenyl or a group comprising napthyl; R? represents a substituent group; R??H or a substituent; n=0, 1, 2 or 3; m=0 or 1; and n?=1 or 2, with the proviso that m=0 if n=0.