Organic Optoelectronic Device Lab (OODL), Department of Information Display, Kyung Hee University, 26, Kyungheedae-ro, Dongdaemun-gu, Seoul, 02447, Republic of Korea.
Nat Commun. 2023 Jan 26;14(1):419. doi: 10.1038/s41467-023-35926-1.
The hyperfluorescence (HF) system has drawn great attention in display technology. However, the energy loss mechanism by low reverse intersystem crossing rate (k) and the Dexter energy transfer (DET) channel is still challenging. Here, we demonstrate that this can be mitigated by the quadrupolar donor-acceptor-donor (D-A-D) type of thermally activated delayed fluorescence (TADF) sensitizer materials, DBA-DmICz and DBA-DTMCz. Further, the HF device with DBA-DTMCz and ν-DABNA exhibited 43.9% of high maximum external quantum efficiency (EQE) with the Commission Internationale de l'Éclairage coordinates of (0.12, 0.16). The efficiency values recorded for the device are among the highest reported for HF devices. Such high efficiency is assisted by hindered DET process through i) high k, and ii) shielded lowest unoccupied molecular orbital with the presence of two donors in D-A-D type of skeleton. Our current study provides an effective way of designing TADF sensitizer for future HF technology.
该超荧光（HF）系统在显示技术中引起了广泛关注。然而，低反向系间穿越率（k）和 Dexter 能量转移（DET）通道的能量损失机制仍然具有挑战性。在这里，我们证明，通过四极供体-受体-供体（D-A-D）型热激活延迟荧光（TADF）敏化材料 DBA-DmICz 和 DBA-DTMCz 可以减轻这种情况。此外，具有 DBA-DTMCz 和 ν-DABNA 的 HF 器件表现出 43.9%的高最大外量子效率（EQE），国际照明委员会（Commission Internationale de l'Éclairage）坐标为（0.12，0.16）。该器件记录的效率值在 HF 器件的最高报道效率中名列前茅。通过以下方式提高了效率：i）高 k，和 ii）通过在 D-A-D 型骨架中存在两个供体来屏蔽最低未占据分子轨道。我们目前的研究为未来 HF 技术的 TADF 敏化剂设计提供了一种有效途径。
