Novel, blue light-emitting polyfluorenes containing a fluorinated quinoxaline unit

A series of fluorinated quinoxaline containing polyfluorenes were synthesized by Suzuki polycondensation. The polymer light emitting diodes based on the resulting copolymers emitted blue light, and no green emission was observed either in the photoluminescence spectra when the film had been annealed at 80–160 °C nor in the electroluminescence spectra when the current densities increased from 5 to 200 mA cm−2. The fluorescence quantum yields decreased from 79% to 36% with increasing content of BPFQ from 1 to 20 mol%. Peak external quantum efficiency and luminous efficiency were 2.99% and 2.39 cd A−1, respectively, with CIE coordinates of (0.16, 0.10).