Thermally activated delayed fluorescent (TADF) materials are capable of converting non-radiative triplets into radiative singlets in the presence of a tiny singlet-triplet splitting. Circularly polarized luminescent (CPL) materials with TADF properties have shown great potential in unity exciton utilization as well as high circularly polarized dissymmetry factors |gPL|. When employed in organic light-emitting devices (OLEDs), circularly polarized electroluminescence (CPEL) with high dissymmetry factors |gEL| is essential for reducing the optical loss and improving the quality of 3D, augment-reality, and virtual reality displays. This Perspective summarizes the recent advances in the cutting-edge research of CP-TADF-OLEDs and addresses the challenges in molecular and device engineering.

Purely organic emitters have shown great potential but still suffer from low efficiency in nearinfrared organic light-emitting diodes (NIR-OLEDs) due to the intensive non-radiative recombination. In this contribution, two pairs of thermally activated delayed fluorescence (TADF) enantiomers (R/S-DOBP and R/S-HDOBP) with tetracoordinate boron geometries were designed and synthesized. The TADF emitters simultaneously showed aggregation-induced emission, circularly polarized luminescence, high-contrast mechanochromism, and piezochromism behaviors. More importantly, R/S-DOBP and R/S-HDOBP revealed high photoluminescence quantum yields and efficient reverse intersystem crossing in neat films. The nondoped solutionprocessed OLEDs based on these unique emitters revealed the NIR emission (peaking at 716 nm) with a maximum external quantum efficiency of 1.9 % and high exciton utilization efficiency of 86 %, which represent one of the best solution-processed nondoped NIR-OLEDs.

No abstract

No abstract

Purely organic emitters have shown great potential but still suffer from low efficiency in nearinfrared organic light-emitting diodes (NIR-OLEDs) due to the intensive non-radiative recombination. In this contribution, two pairs of thermally activated delayed fluorescence (TADF) enantiomers (R/S-DOBP and R/S-HDOBP) with tetracoordinate boron geometries were designed and synthesized. The TADF emitters simultaneously showed aggregation-induced emission, circularly polarized luminescence, high-contrast mechanochromism, and piezochromism behaviors. More importantly, R/S-DOBP and R/S-HDOBP revealed high photoluminescence quantum yields and efficient reverse intersystem crossing in neat films. The nondoped solutionprocessed OLEDs based on these unique emitters revealed the NIR emission (peaking at 716 nm) with a maximum external quantum efficiency of 1.9 % and high exciton utilization efficiency of 86 %, which represent one of the best solution-processed nondoped NIR-OLEDs.