TY - JOUR
T1 - Thermally Activated Delayed Fluorescence Warm White Organic Light Emitting Devices with External Quantum Efficiencies Over 30%
AU - Chen, Jia-Xiong
AU - Wang, Kai
AU - Xiao, Ya-Fang
AU - Cao, Chen
AU - Tan, Ji-Hua
AU - Wang, Hui
AU - Fan, Xiao-Chun
AU - Yu, Jia
AU - Geng, Feng-Xia
AU - Zhang, Xiao-Hong
AU - Lee, Chun-Sing
PY - 2021/8
Y1 - 2021/8
N2 - While monochrome organic light-emitting diodes (OLEDs) based on thermally activated delayed fluorescence (TADF) emitters have achieved over 30% external quantum efficiencies (EQEs), all-TADF white OLEDs (WOLEDs) are still lagging behind. Herein, a simple system based on two color-complementary TADF emitters is exploited to realize high-performance WOLEDs. By doping a high-performance orange–red TADF fluorophor (BPPZ-DPXZ) into a blue TADF host (DBFCz-Trz), energy transfer, and triplet-to-singlet conversion in the host-dopant system can be optimized to simultaneously achieve full exciton utilization and color balance. With this design, all-TADF single-emitting-layer WOLEDs with a maximum EQE up to 32.8% are demonstrated. This high efficiency surpasses EQEs of reported WOLEDs based on both TADF as well as phosphorescence. It is expected that this finding can provide new insight for designing highly efficient all-TADF WOLEDs.
AB - While monochrome organic light-emitting diodes (OLEDs) based on thermally activated delayed fluorescence (TADF) emitters have achieved over 30% external quantum efficiencies (EQEs), all-TADF white OLEDs (WOLEDs) are still lagging behind. Herein, a simple system based on two color-complementary TADF emitters is exploited to realize high-performance WOLEDs. By doping a high-performance orange–red TADF fluorophor (BPPZ-DPXZ) into a blue TADF host (DBFCz-Trz), energy transfer, and triplet-to-singlet conversion in the host-dopant system can be optimized to simultaneously achieve full exciton utilization and color balance. With this design, all-TADF single-emitting-layer WOLEDs with a maximum EQE up to 32.8% are demonstrated. This high efficiency surpasses EQEs of reported WOLEDs based on both TADF as well as phosphorescence. It is expected that this finding can provide new insight for designing highly efficient all-TADF WOLEDs.
KW - energy transfer
KW - single emitting-layer
KW - thermally activated delayed fluorescence
KW - white organic light-emitting diodes
UR - http://www.scopus.com/inward/record.url?scp=85106994241&partnerID=8YFLogxK
UR - https://www.scopus.com/record/pubmetrics.uri?eid=2-s2.0-85106994241&origin=recordpage
U2 - 10.1002/adfm.202101647
DO - 10.1002/adfm.202101647
M3 - RGC 21 - Publication in refereed journal
SN - 1616-301X
VL - 31
JO - Advanced Functional Materials
JF - Advanced Functional Materials
IS - 31
M1 - 2101647
ER -