Multi-Resonance Emitters (MREs) are a promising candidate for fulfilling the harsh requirements of display applications due to their unique photophysical properties. Recently, MREs have been widely used as a Terminal Emitter (TE) in Hyper Fluorescence Organic Light-Emitting Diodes (HF-OLEDs); however, since MREs are always TADF-active, possessing long triplet lifetimes in milli-second order, they result in severe chemical degradation. The device lifetime of blue OLED is still a challenge. Here, instead of shortening the delayed lifetime of MREs by molecular design, we introduced a low-triplet pyrene unit into an MRE scaffold to achieve narrowband emission and quick removal of triplets in MREs simultaneously. Blue HF-OLED based on the non-TADF MRE demonstrated a high external quantum efficiency (EQE) of 20% and a ten-fold improvement in stability, compared to those of the HF-OLEDs with standard MREs.
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