TY - JOUR
T1 - Red/Near-Infrared Thermally Activated Delayed Fluorescence OLEDs with Near 100 % Internal Quantum Efficiency
AU - Chen, Jia-Xiong
AU - Tao, Wen-Wen
AU - Chen, Wen-Cheng
AU - Xiao, Ya-Fang
AU - Wang, Kai
AU - Cao, Chen
AU - Yu, Jia
AU - Li, Shengliang
AU - Geng, Feng-Xia
AU - Adachi, Chihaya
AU - Lee, Chun-Sing
AU - Zhang, Xiao-Hong
PY - 2019/10/7
Y1 - 2019/10/7
N2 - Developing red thermally activated delayed fluorescence (TADF) emitters, attainable for both high-efficient red organic light-emitting diodes (OLEDs) and non-doped deep red/near-infrared (NIR) OLEDs, is challenging. Now, two red emitters, BPPZ-PXZ and mDPBPZ-PXZ, with twisted donor–acceptor structures were designed and synthesized to study molecular design strategies of high-efficiency red TADF emitters. BPPZ-PXZ employs the strictest molecular restrictions to suppress energy loss and realizes red emission with a photoluminescence quantum yield (ΦPL) of 100±0.8 % and external quantum efficiency (EQE) of 25.2 % in a doped OLED. Its non-doped OLED has an EQE of 2.5 % owing to unavoidable intermolecular π–π interactions. mDPBPZ-PXZ releases two pyridine substituents from its fused acceptor moiety. Although mDPBPZ-PXZ realizes a lower EQE of 21.7 % in the doped OLED, its non-doped device shows a superior EQE of 5.2 % with a deep red/NIR emission at peak of 680 nm.
AB - Developing red thermally activated delayed fluorescence (TADF) emitters, attainable for both high-efficient red organic light-emitting diodes (OLEDs) and non-doped deep red/near-infrared (NIR) OLEDs, is challenging. Now, two red emitters, BPPZ-PXZ and mDPBPZ-PXZ, with twisted donor–acceptor structures were designed and synthesized to study molecular design strategies of high-efficiency red TADF emitters. BPPZ-PXZ employs the strictest molecular restrictions to suppress energy loss and realizes red emission with a photoluminescence quantum yield (ΦPL) of 100±0.8 % and external quantum efficiency (EQE) of 25.2 % in a doped OLED. Its non-doped OLED has an EQE of 2.5 % owing to unavoidable intermolecular π–π interactions. mDPBPZ-PXZ releases two pyridine substituents from its fused acceptor moiety. Although mDPBPZ-PXZ realizes a lower EQE of 21.7 % in the doped OLED, its non-doped device shows a superior EQE of 5.2 % with a deep red/NIR emission at peak of 680 nm.
KW - molecular design
KW - OLEDs
KW - red/near-IR emission
KW - rigid segments
KW - thermally activated delayed fluorescence
UR - http://www.scopus.com/inward/record.url?scp=85070751736&partnerID=8YFLogxK
UR - https://www.scopus.com/record/pubmetrics.uri?eid=2-s2.0-85070751736&origin=recordpage
U2 - 10.1002/anie.201906575
DO - 10.1002/anie.201906575
M3 - RGC 21 - Publication in refereed journal
SN - 1433-7851
VL - 58
SP - 14660
EP - 14665
JO - Angewandte Chemie (International Edition)
JF - Angewandte Chemie (International Edition)
IS - 41
ER -