High-performance blue light-emitting diode based on a binaphthyl-containing polyfluorene

We report efficient blue electroluminescence (EL) from multilayer polymer light-emitting diodes using a binaphthyl-containing polyfluorene as the emitting layer and a series of thermally polymerized triphenylamine/tetraphenyldiaminobiphenyl-containing polymers as the hole transport layer. The polymer possesses a high photoluminescence quantum efficiency of 44%. The polymer light-emitting diodes exhibit EL emission peak at 420 or 446 nm, depending on the hole transporting materials. The EL reaches maximum brightness and external quantum efficiency of 3070 cd/m2 and 0.82%, respectively.