ae7b00131_si_001.pdf (1.21 MB)
Highly Efficient, Solution-Processed Organic Light-Emitting Diodes Based on Thermally Activated Delayed-Fluorescence Emitter with a Mixed Polymer Interlayer
journal contribution
posted on 2018-01-29, 00:00 authored by Yanwei Liu, Xiaofang Wei, Zhiyi Li, Jianjun Liu, Ruifang Wang, Xiaoxiao Hu, Pengfei Wang, Yukiko Yamada-Takamura, Ting Qi, Ying WangThe efficiency of
solution-processed organic light-emitting diodes based on pure organic
thermally activated delayed-fluorescence (TADF) emitters is limited
by the hole-injection/severe exciton quenching of poly(styrenesulfonate)-doped
poly(3,4-ethylenedioxythiophene) (PEDOT:PSS) and the exction quenching
of TADF emitters due to the self-aggregation. In order to effectively
enhance the hole-injection from PEDOT:PSS and to alleviate the exciton
quenching of the PEDOT:PSS, the mixed interlayer of poly(9-vinylcarbazole)
(PVK) and poly[(9,9-dioctylfluorenyl-2,7-diyl)-co-(4,4′-(N-(4-s-butylphenyl)diphenylamine))
(TFB) was inserted between emitting layer (EML) and the PEDOT:PSS
layer. Additionally, the cohost of 3′,5′-di(carbazol-9-yl)-[1,1′-biphenyl]-3,5-dicarbonitrile
(DCzDCN) and bis(3,5-di(9H-carbazol-9-yl)phenyl)diphenylsilane
(SimCP2) was used to suppress the self-aggregation of the TADF emitter
of 2-(9-phenyl-9H-carbazol-3-yl)-10,10-dioxide-9
thioxanthone (TXO-PhCz) and tune the charge carrier transport. By
optimizing the mix ratio, highly efficient, solution-processed, green-emitting
TADF-OLEDs with the hole-transport layer (HTL) of TFB:PVK (1:1) and
the EML host of DCzDCN:SimCP2 (1:2) can be turned on at 4 V and can
show a maximum current efficiency (CE) of 55.6 cd/A, a maximum power
efficiency (PE) of 47.2 lm/W, and an external quantum efficiency (EQE)
of 18.86%. The devices are among the most efficient OLEDs fabricated
by solution-processed methods. These results indicate that the employment
of a mixed HTL and EML cohost is a promising way toward the high-efficiency
solution-processed OLEDs.
History
Usage metrics
Categories
Keywords
carbazol -3-yl thioxanthoneEML cohostPEmix ratiopower efficiencyhole-injectionEQETADF emitterself-aggregationTADF emittersPEDOThigh-efficiency solution-processed OLEDsexction quenchinglight-emitting diodesHTLhole-transport layerpolyquantum efficiencycarbazol -9-ylDCzDCNPVKMixed Polymer InterlayerCEexciton quenchingSolution-Processed Organic Light-Emitting Diodessolution-processed methodsEML host4 Vgreen-emitting TADF-OLEDscharge carrier transportThermally Activated Delayed-Fluorescence EmitterTFB
Licence
Exports
RefWorks
BibTeX
Ref. manager
Endnote
DataCite
NLM
DC