6‐4: Late‐News Paper: Realizing Deep Blue Emission in Blue Phosphorescent Organic Light‐Emitting Diodes

2020 ◽  
Vol 51 (1) ◽  
pp. 65-66
Author(s):  
Jinwon Sun ◽  
Hyein Jeong ◽  
Jaejin Lyu
Author(s):  
Bo-Sun Yun ◽  
So-Yoen Kim ◽  
Jin-Hyoung Kim ◽  
Ho-Jin Son ◽  
Sang Ook Kang

The NHC-Ir complexes f-IrSiPr, m-IrSiPr, and m-IrSMe, in which a dibenzothiophene (DBT) moiety is used to increase the emission efficiency for deep-blue phosphorescence, were synthesized and compared with the dibenzofuran...


Materials ◽  
2021 ◽  
Vol 14 (3) ◽  
pp. 554
Author(s):  
Taeshik Earmme

Solution-processed blue phosphorescent organic light-emitting diodes (PHOLEDs) based on a single emission layer with small-molecule hole-transport materials (HTMs) are demonstrated. Various HTMs have been readily incorporated by solution-processing to enhance hole-transport properties of the polymer-based emission layer. Poly(N-vinylcarbazole) (PVK)-based blue emission layer with iridium(III) bis(4,6-(di-fluorophenyl)pyridinato-N,C2′)picolinate (FIrpic) triplet emitter blended with solution-processed 1,1-bis[(di-4-tolylamino)phenyl]cyclohexane (TAPC) gave luminous efficiency of 21.1 cd/A at a brightness of 6220 cd/m2 with an external quantum efficiency (EQE) of 10.6%. Blue PHOLEDs with solution-incorporated HTMs turned out to be 50% more efficient compared to the reference device without HTMs. The high hole mobility, high triplet energy of HTM, and favorable energy transfer between HTM blended PVK host and FIrpic blue dopant were found to be important factors for achieving high device performance. The results are instructive to design and/or select proper hole-transport materials in solution-processed single emission layer.


Molecules ◽  
2021 ◽  
Vol 26 (18) ◽  
pp. 5568
Author(s):  
Jie Li ◽  
Heqi Gong ◽  
Jincheng Zhang ◽  
Hui Liu ◽  
Li Tao ◽  
...  

The realization of a deep-blue-emitting exciplex system is a herculean task in the field of organic light-emitting diodes (OLEDs) on account of a large red-shifted and broadened exciplex emission spectrum in comparison to those of the corresponding single compounds. Herein, 2,5,8-tris(di(4-fluorophenyl)amine)-1,3,4,6,7,9,9b-heptaazaphenalene (HAP-3FDPA) was designed as an electron acceptor by integrating three bis(4-fluorophenyl)amine groups into a heptazine core, while 1,3-di(9H-carbazol-9-yl)benzene (mCP) possessing two electron-donating carbazole moieties was chosen as the electron donor. Excitingly, the exciplex system of 8 wt% HAP-3FDPA:mCP exhibited deep-blue emission and a high photoluminescence quantum yield of 53.2%. More importantly, an OLED containing this exciplex system as an emitting layer showed deep-blue emission with Commission Internationale de l’Eclairage coordinates of (0.16, 0.12), a peak luminance of 15,148 cd m−2, and a rather high maximum external quantum efficiency of 10.2% along with a low roll-off. This study not only reports an efficient exciplex-based deep-blue emitter but also presents a feasible pathway to construct highly efficient deep-blue OLEDs based on exciplex systems.


2021 ◽  
Author(s):  
XinYe Wang ◽  
Yuan Wu ◽  
ChuanMing Wu ◽  
Yixiang Li ◽  
Dongdong Wang ◽  
...  

Two novel molecular scaffolds, dibenzo[f,h]furo[2,3-b]quinoxaline (diBFQ) and its derivative, 3,6-bis(4-isopropylphenyls)-11-phenyldibenzo[f,h]furo[2,3-b]quinoxaline (dP-diBFQ), and furo[2',3':5,6]pyrazino[2,3-f][1,10]phenanthroline (FPPhen), were designed and syn-thesized for highly efficient pure and deep blue emission. The unsubstituted molecule scaffold...


2017 ◽  
Vol 9 (43) ◽  
pp. 37883-37887 ◽  
Author(s):  
Hyoungcheol Lim ◽  
Hyun Shin ◽  
Kwon-Hyeon Kim ◽  
Seung-Jun Yoo ◽  
Jin-Suk Huh ◽  
...  

2017 ◽  
Vol 5 (7) ◽  
pp. 1651-1659 ◽  
Author(s):  
Yang-Jin Cho ◽  
So-Yoen Kim ◽  
Jin-Hyoung Kim ◽  
Jiwon Lee ◽  
Dae Won Cho ◽  
...  

The photophysical and electrochemical properties of the two isomeric N-heterocyclic carbene Ir(iii) complexes were investigated.


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