Triptycene-derived TADF enantiomers displaying circularly polarized luminescence and high-efficiency electroluminescence

Abstract A pair of novel circularly polarized thermally activated delayed fluorescence (CP-TADF) enantiomers (+)-(S,S)-CTRI-Cz and (−)-(R,R)-CTRI-Cz based on chiral triptycene scaffold were designed and synthesized. The obtained triptycene-derived enantiomers displayed obvious TADF activities with small singlet-triplet energy gap value (ΔEST) of 0.20 eV and characteristic microsecond delayed lifetime of 15.4 μs. Moreover, the TADF enantiomers showed mirror-image circular dichroism (CD) and circularly polarized luminescence (CPL) activities, and their luminescence dissymmetry factors (glum) were about ±0.9 × 10−3. Finally, by using the TADF enantiomers as emitters, the optimized organic light-emitting diodes (OLEDs) achieved maximum external quantum efficiency (EQEmax), current efficiency (CEmax) and power efficiency (PEmax) of 15.0%, 48.8 cd/A and 46.9 lm/W, respectively.