An efficient “hot exciton” fluorophore based on a dicyanophenanthrene-triphenylamine hybrid

The study presents the design, synthesis, and characterization of DCNP-2TPA, a novel "hot exciton" fluorophore featuring a donor-acceptor structure combining dicyanophenanthrene and triphenylamine. Through a comprehensive analysis including structural examination, theoretical modeling, and optical assessments, the suitability of DCNP-2TPA for integration into organic light-emitting diodes (OLEDs) is evaluated. Comparative to existing dicyanophenanthrene-based emitters, DCNP-2TPA demonstrates significantly enhanced luminescence efficiency, by virtue of the incorporation of triphenylamine moieties with moderate electron-donating strength. Furthermore, DCNP-2TPA exhibits aggregation-induced emission (AIE) properties and showcases hybridized local and charge-transfer (HLCT) excited states, offering an efficient "hot exciton" channel for triplet harvesting. Employing DCNP-2TPA as the emissive core, OLED devices achieve a noteworthy external quantum efficiency of 8.42%, highlighting the promise of DCNP-2TPA as an efficient candidate for OLED applications.