Combining the qualities of carbazole and tetraphenyl silane in a desirable main chain for thermally activated delayed fluorescence polymers

Abstract

Thermally activated delayed fluorescence (TADF) polymers have attracted considerable interest for their use in spin-coated electroluminescent devices. Inspired by a side chain engineering strategy for developing highly efficient TADF polymers, a series of green TADF polymers with varying ratios of TADF moiety dangled at the side chain were designed and synthesized. The copolymer main backbones comprise both a non-conjugated tetraphenyl-silicon moiety and a conjugated carbazole unit. All these TADF polymers exhibited high photoluminescence quantum yields in the neat films and the highest one was 0.71. The non-doped, solution processed polymer light emitting diodes using these polymers as the emitting layers achieved good performance with a maximum external quantum efficiency of 7.0%.