Cascade Chirality Transfer Through Diastereomeric Interaction Enables Efficient Circularly Polarized Electroluminescence

Organic light-emitting diodes (OLEDs) with circularly polarized emission can bring a breakthrough innovation in display technologies. However, it remains challenging due to the difficulty in obtaining high efficiency and large dissymmetry factor simultaneously. Herein, it is demonstrated that robust circularly polarized (CP) electroluminescence can be induced by cascade chirality transfer within the emitting layer. Through spectroscopic data and theoretical analysis, the initiation of this chirality transfer process is assigned to diastereomeric interaction. Utilizing this interaction and excellent Forster resonance energy transfer ability to the well-known racemic emitter, CP-OLEDs with an electroluminescence dissymmetry factor (|g(EL)|) up to 3.2 x 10(-3) and high external quantum efficiency (EQE) of 32% are successfully fabricated. These devices also show ultra-low efficiency roll-off at high brightness, with EQE >= 20% at 128 000 cd m(-2). This study paves the way for the future development of CP-OLEDs through synergistic materials and device engineering.