A new strategy of thermally activated delayed fluorescence (TADF) material-sensitized circularly polarized luminescence (CPL) has been proposed for improving the efficiencies of fluorescent circularly polarized organic light-emitting diodes (OLEDs) (CP-OLEDs). Consequently, a pair of helicene enantiomers, (P)-HAI and (M)-HAI, were synthesized. The helicene enantiomers with the rigid helical π-skeleton had highly thermal and enantiomeric stabilities, and they also showed excellent photophysical properties, especially, intense mirror-image CPL activities with large luminescence dissymmetry factor (|g_lum|) values of about 6 × 10⁻³. Notably, the CP-OLEDs with the helicene enantiomers as emitters and a TADF molecule as sensitizer not only displayed better performance of lower turn-on voltage (V_T) of 2.6 V, four-fold maxmium-external quantum efficiency (EQE_max) of 5.3%, and lower efficiencies roll-off of 1.9% at 1000 cd m⁻², than those of the devices without TADF sensitizer, but also exhibited intense circularly polarized electroluminescence (CPEL) with the electroluminescence dissymmetry factor (g_EL) values of −2.3 × 10⁻³ and +3.0 × 10⁻³. Meanwhile, this study also represents the first thermally activated sensitized fluorescent CP-OLEDs with markedly enhanced efficiencies and intense CPEL.

为了提高荧光圆偏振有机发光二极管（OLED）（CP-OLED）的效率，已经提出了热活化延迟荧光（TADF）材料敏化的圆偏振发光（CPL）的新策略。因此，合成了一对螺旋烯对映体，（P）-HAI和（M）-HAI。具有刚性螺旋π骨架的he烯对映体具有很高的热稳定性和对映体稳定性，并且还显示出优异的光物理性质，尤其是具有强烈的镜像CPL活性，且发光不对称系数（| g _lum |）值约为6×10 ⁻³。值得注意的是，以螺旋烯对映体为发射体和TADF分子作为敏化剂的CP-OLED不仅表现出更好的性能，即2.6 V的较低开启电压（V _T），4倍的最大-外部量子效率（EQE _max）。与没有TADF增感剂的器件相比，在1000 cd m ^-2时具有5.3％的效率和1.9％的较低效率滚降，但还具有强烈的圆偏振电致发光（CPEL），电致发光不对称因子（g _EL）值为- 2.3×10 ^-3和+3.0×10 ^-3。同时，这项研究也代表了首批具有显着增强的效率和强烈的CPEL的热活化敏化荧光CP-OLED。