Highly Efficient Purely Organic Phosphorescence Light-Emitting Diodes Employing a Donor-Acceptor Skeleton with a Phenoxaselenine Donor

作者：Chen, Zijian; Li, Mengke; Gu, Qing; Peng, Xiaomei; Qiu, Weidong; Xie, Wentao; Liu, Denghui; Jiao, Yihang; Liu, Kunkun; Zhou, Jiadong; Su, Shi-Jian^*

来源：Advanced Science, 2023, 10(12).

DOI：10.1002/advs.202207003

• organic light-emitting diode
• phenoxaselenine
• room-temperature phosphorescence
• single-molecule white emission

Purely organic room-temperature phosphorescence (RTP) materials generally exhibit low phosphorescence quantum yield (phi(P)) and long phosphorescence lifetime (tau(P)) due to the theoretically spin-forbidden triplet state. Herein, by introducing a donor-acceptor (D-A) skeleton with a phenoxaselenine donor, three nonaromatic amine donor containing compounds with high phi(P) and short tau(P) in amorphous films are developed. Besides the enhanced spin-orbit coupling (SOC) by the heavy-atom effect of selenium, the D-A skeleton which facilitates orbital angular momentum change can further boost SOC, and severe nonradiative energy dissipation is also suppressed by the rigid molecular structure. Consequently, a record-high external quantum efficiency of 19.5% are achieved for the RTP organic light-emitting diode (OLED) based on 2-(phenoxaselenin-3-yl)-4,6-diphenyl-1,3,5-triazine (PXSeDRZ). Moreover, voltage-dependent color-tunable emission and single-molecule white emission are also realized. These results shed light on the broad prospects of purely organic phosphorescence materials as highly efficient OLED emitters especially for potential charming lighting applications.