Abstract
The aggregation-induced emission (AIE) phenomenon provides a new direction for the development of organic light-emitting devices. Here, we present a new class of emitters based on 4,4-difluoro-4-bora-3a,4a-diaza-s-indacene (BODIPY), functionalized at different positions with tetraphenylethylene (TPE), which is one of the most famous AIE luminogens. Thanks to this modification, we were able to tune the photoluminescence of the BODIPY moiety from the green to the near-infrared (NIR) spectral range and achieve PL efficiencies of similar to 50% in the solid state. Remarkably, we observed an enhancement of the AIE and up to similar to 100% photoluminescence efficiencies by blending the TPE-substituted BODIPY fluorophores with a poly[(9,9-di-n-octylfluorene-2,7-diyl)-alt-(benzo[2,1,3]thiadiazol-4,7-diyl)] (F8BT) matrix. By incorporating these blends in organic light-emitting diodes (OLEDs), we obtained electroluminescence peaked in the range 650-700 nm with up to 1.8% external quantum efficiency and similar to 2 mW/cm(2) radiance, a remarkable result for red/NIR emitting and solution-processed OLEDs.