White phosphorescent polymer light-emitting devices based on a wide band-gap polymer derived from 3,6-carbazole and tetraphenylsilane

A wide band-gap polymer derived from 3,6-carbazole and tetraphenylsilane has been employed as a host for ternary phosphorescent iridium complexes in a white polymer light-emitting device (PLED). By studying both electroluminescence and photoluminescence of the doped polymeric light-emitting layer, it was found that both energy transfer and direct trapping attribute to the emission. Balanced white light with an external quantum efficiency of 4.26%, corresponding to a luminous efficiency of 8.55 cd/A and a power efficiency of 4.55 lm/W, as well as a color rendering index of 82 were achieved at 100 cd/m2.