Simultaneous realization of high-efficiency, low-drive voltage, and long lifetime TADF OLEDs by multifunctional hole-transporters

2020 ◽  
Vol 8 (21) ◽  
pp. 7200-7210 ◽  
Author(s):  
Takahiro Kamata ◽  
Hisahiro Sasabe ◽  
Nozomi Ito ◽  
Yoshihito Sukegawa ◽  
Ayato Arai ◽  
...  

A smart high-triplet energy hole-transporter exhibits significant stability in the anion state realizing record-breaking highly efficient and long-living thermally activated delayed fluorescent (TADF) organic light-emitting devices (OLEDs).

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Maria Vasilopoulou ◽  
Abd. Rashid bin Mohd Yusoff ◽  
Matyas Daboczi ◽  
Julio Conforto ◽  
Anderson Emanuel Ximim Gavim ◽  
...  

AbstractBlue organic light-emitting diodes require high triplet interlayer materials, which induce large energetic barriers at the interfaces resulting in high device voltages and reduced efficiencies. Here, we alleviate this issue by designing a low triplet energy hole transporting interlayer with high mobility, combined with an interface exciplex that confines excitons at the emissive layer/electron transporting material interface. As a result, blue thermally activated delay fluorescent organic light-emitting diodes with a below-bandgap turn-on voltage of 2.5 V and an external quantum efficiency (EQE) of 41.2% were successfully fabricated. These devices also showed suppressed efficiency roll-off maintaining an EQE of 34.8% at 1000 cd m−2. Our approach paves the way for further progress through exploring alternative device engineering approaches instead of only focusing on the demanding synthesis of organic compounds with complex structures.


2019 ◽  
Vol 7 (40) ◽  
pp. 12695-12703 ◽  
Author(s):  
Ji Seon Jang ◽  
Ha Lim Lee ◽  
Kyung Hyung Lee ◽  
Jun Yeob Lee

Pyrimidine-5-carbonitrile was developed as an electrostatic potential managing and strong acceptor moiety of thermally activated delayed fluorescent (TADF) emitters for high efficiency and long lifetime in devices.


2019 ◽  
Vol 10 (35) ◽  
pp. 4872-4878 ◽  
Author(s):  
Yun Hwan Park ◽  
Ho Jin Jang ◽  
Jun Yeob Lee

A highly efficient polymeric thermally activated delayed fluorescent (TADF) organic light-emitting diode was developed by synthesizing a copolymer with 9-vinylcarbazole (VCz) and TADF repeating units.


2020 ◽  
Vol 8 (15) ◽  
pp. 5265-5272 ◽  
Author(s):  
Ji Han Kim ◽  
Kyung Hyung Lee ◽  
Jun Yeob Lee

Yellow thermally activated delayed fluorescence materials were synthesized using two types of acceptors of 2,4,6-triphenylpyrimidine-5-carbonitrile and 4-(3-cyanophenyl)-2,6-diphenylpyrimidine-5-carbonitrile combined with a strong donor.


2007 ◽  
Vol 364-366 ◽  
pp. 1095-1099
Author(s):  
Wen Long Jiang ◽  
Yu Duan ◽  
Hui Ying Li ◽  
De Chang Li ◽  
Gui Ying Ding

Highly efficient and unusual structures white organic light-emitting devices were fabricated based on phosphorescence sensitized 5,6,11,12-tetraphenylnaphthacene. The device structure was ITO / NPB (30 nm)/CBP: 10% DPVBi (10 nm)/CBP (5 nm) /CBP:x% Ir(ppy)3 : y% rubrene (20 nm)/ CBP (5 nm)/ CBP: 10% DPVBi (10 nm)/BCP (10 nm)/ Alq3 (30 nm)/LiF(0.5 nm)/Al, where NPB is N,N '-bis- (1-naphthyl)- N,N ' –diphenyl -1, 1 '- biphenyl-4,4 '-diamine as a hole transporting layer, CBP 4,4,N,N’-dicarbazolebiphenyl as host,DPVBi is 4,4 '-bis(2,2 -diphenyl vinyl)-1,1 '-biphenyl as blue fluorescent dye,Rubrene is 5,6,11,12,-tetraphenylnaphthacene as fluorescent dye,Ir(ppy)3 is factris (2-phenylpyridine) iridium as phosphorescent sensitizer .BCP is 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline as hole-blocking layer, and Alq3 is tris(8- hydroxyquinoline) aluminum as an electron-transporting layer. In this device, phosphorescent emissive layer was sandwiched between two blue fluorescent doped ones. This architecture allowed for resonant energy transfer from both the host singlet and triplet energy levels that minimized exchange energy losses. Thus, a WOLED with a maximum luminous efficiency of 11.63 cd/A, a maximum power efficiency of 7.37 lm/W, a maximum luminance of 31770cd/m2, and Commission Internationale de L’Eclairage coordinates of (0.34.0.36) was achieved.


Author(s):  
Ha Lim Lee ◽  
Kyung Hyung Lee ◽  
Jun Yeob Lee ◽  
Ho Jung Lee

High efficiency and long lifetime thermally activated delayed fluorescent (TADF) organic light-emitting diodes (OLEDs) were developed using a novel molecular design with two emission pathways for high photoluminescence quantum yield...


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