Hyperbranched triazine-containing polyfluorenes: Efficient blue emitters for polymer light-emitting diodes (PLEDs)

A series of hyperbranched triazine-containing polyfluorenes were synthesized by an “A2 + A′2 + B3” approach based on Suzuki polycodensation. The polymers showed pure blue emission and the maximum emissions red-shifted in polar solvents and in solid film. By introducing triazine into polyfluorene, the electron injection and transport properties were improved and green emission was suppressed. PLED devices fabricated with the polymers showed reasonably high external quantum efficiencies.