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

We report efficient blue electroluminescence (EL) from multilayer polymer l ight-emitting diodes using a binaphthyl-containing polyfluorene as the emit ting layer and a series of thermally polymerized triphenylamine/tetraphenyl diaminobiphenyl-containing polymers as the hole transport layer. The polyme r 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/m(2) and 0.82%, respectively. (C) 20 00 American Institute of Physics. [S0003-6951(00)04714-8].