Chiral thermally activated delayed fluorescence emitters for circularly polarized luminescence and efficient deep blue OLEDs

Abstract The development of the thermally activated delayed fluorescence (TADF) emitters with circularly polarized luminescence (CPL), particularly those exhibiting deep-blue emission is still a formidable challenge. In this work, we reported a simple and easily accessed molecular design strategy for deep-blue circularly polarized TADF (CP-TADF) enantiomers. Two chiral compounds, namely (S)-NPE-AcDPS and (R)-NPE-AcDPS, were successfully designed and synthesized, which featured concurrently TADF, CPL, and aggregation-induced enhanced emission (AIEE) properties. The CPL exhibited a maximum gPL value of 3.0 × 10−4. These emitters exhibited deep blue emission peaking at 451 nm in doped film with a high photoluminescence of 86% and a small singlet-triplet splitting of 0.05 eV. Furthermore, the deep blue OLED based on (S)-NPE-AcDPS demonstrated a high external quantum efficiency (EQE) up to 18.5%.