scholarly journals Non-Doped Deep-Blue OLEDs Based on Carbazole-π-Imidazole Derivatives

Materials ◽  
2021 ◽  
Vol 14 (9) ◽  
pp. 2349
Author(s):  
Pengfei Yu ◽  
Yin Xiao

In this work, we designed and synthesized four bipolar blue-emitting materials with carbazole, imidazole, and biphenyl as donor, acceptor, and p bridge, respectively. The twisted phenylimidazole acceptor leads to a wider band-gap and hence deeper blue emission than the conjugated phenanthrimidazole acceptor. For the substituents on the carbazole donor, the t-butyl group could prevent the intramolecular charge transfer (ICT) process more effectively than the methoxy group. A non-doped deep-blue organic light-emitting diodes (OLED) is obtained with CIE coordinates of (0.159, 0.080), a maximum luminance of 11364 cd/m2, and a maximum EQE of 4.43%.

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...


RSC Advances ◽  
2016 ◽  
Vol 6 (74) ◽  
pp. 70085-70090 ◽  
Author(s):  
Haichao Liu ◽  
Qing Bai ◽  
Weijun Li ◽  
Yachen Guo ◽  
Liang Yao ◽  
...  

Acceptor–donor–acceptor triphenylamine–phenanthroimidazole derivate (TPA–2PPI) servers as an emitter, whose device exhibits deep-blue emission, high efficiency and slow roll-off of efficiency.


2018 ◽  
Vol 30 (3) ◽  
pp. 857-863 ◽  
Author(s):  
Seung-Je Woo ◽  
Youheon Kim ◽  
Myeong-Jong Kim ◽  
Jang Yeol Baek ◽  
Soon-Ki Kwon ◽  
...  

2008 ◽  
Vol 8 (9) ◽  
pp. 4607-4610
Author(s):  
Jung Hyun Park ◽  
Ji Hoon Seo ◽  
Ji Hyun Seo ◽  
Seok Jae Lee ◽  
Ja Ryong Koo ◽  
...  

High-efficiency white organic light-emitting diodes (WOLEDs) were fabricated with two emissive layers and an exciton blocking layer (EBL) was sandwiched between two phosphorescent dyes, bis(3,5-difluoro-2-(2-pyridyl)phenyl-(2-carboxypyridyl) iridium III (FIrpic) as the blue emission and iridium(III) bis(5-acetyl-2-phenylpyridinato-N,C2′) acetylacetonate ((acppy)2Ir(acac)) as the red emission. This EBL effectively prevented a triple–triple energy transfer between the two phosphorescent emissive layers with blue and red emission. The white device showed Commission Internationale De L'Eclairage (CIEx,y) coordinates of (0.33, 0.42) at 22400 cd/m2, a maximum luminance of 27300 cd/m2 at 13.2 V, and a maximum luminous efficiency of 26.9 cd/A.


RSC Advances ◽  
2017 ◽  
Vol 7 (20) ◽  
pp. 12150-12160 ◽  
Author(s):  
Paul Kautny ◽  
Chenyang Zhao ◽  
Thomas Kader ◽  
Berthold Stöger ◽  
Ernst Horkel ◽  
...  

1,2,3-Triazole has been applied as a novel linker in donor–acceptor materials to control intramolecular charge transfer phenomena.


RSC Advances ◽  
2015 ◽  
Vol 5 (88) ◽  
pp. 72009-72018 ◽  
Author(s):  
Shuo Chen ◽  
Yukun Wu ◽  
Yi Zhao ◽  
Daining Fang

Novel phenanthroimidazole derivatives with D–π–A structures have been successfully designed and prepared. Non-doped organic light emitting diodes (OLEDs) were fabricated by employing the compounds, which display deep blue emission.


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